1340 ASTRONOMY Study for Test II, Dr. Holtz

If an object’s velocity is doubled, its momentum is

a) dependent on its acceleration.
b) doubled.
c) unchanged.
d) halved.
e) quadrupled.

b

As long as an object is not gaining or losing mass, a constant force applied to an object for a period of time will result in a change in

a) direction.
b) speed.
c) weight.
d) velocity.
e) acceleration.

d

If your mass is 60 kg on Earth, what would your mass be on the Moon?

a) 10 kg
b) 60 lb
c) 10 lb
d) 60 kg
e) 50 kg

d

What would happen if a rocket were launched with a speed greater than Earth’s escape velocity?

a) It would take less time to reach its bound orbit.
b) It would orbit Earth with a faster velocity.
c) It would travel in a higher orbit around Earth.
d) It would travel away from Earth into the solar system.
e) It would be in an unstable orbit

d

Suppose an object is moving in a straight line at 70 km/hr. According to Newton’s first law of motion, the object will

a) continue to move in the same way forever, no matter what happens.
b) continue to move in the same way until it is acted upon by a force.
c) eventually slow down and come to a stop.
d) continue to move in a straight line forever if it is in space, but fall to the ground if it is on Earth.

b

Earth is farthest from the Sun in July and closest to the Sun in January. During which Northern Hemisphere season is Earth moving fastest in its orbit?

a) winter
b) fall
c) spring
d) summer

a

The fact that Voyager 1 continues to speed out of the solar system, even though its rockets have no fuel, is an example of

a) Newton’s first law of motion.
b) Newton’s second law of motion.
c) Newton’s third law of motion.
d) the universal law of gravitation.
e) none of the above

a

Which of two bowling balls accelerate faster during their fall from the same height? Assume the bowling balls are identical, except for their mass.

a) The lighter bowling ball accelerates faster.
b) They both fall with the same acceleration.
c) The heavier bowling ball accelerates faster.

b

The amount of gravitational potential energy released as an object falls depends on

a) the distance it falls.
b) the distance it falls and its speed at the time it begins falling.
c) its speed at the time it begins falling.
d) neither the distance it falls nor its speed at the time it begins falling.

a

Considering Einstein’s equation relating mass and energy, E = mc2, which of the following statements is true?

a) You can make mass into energy if you can accelerate the mass to the speed of light.
b) Mass can be turned into energy, but energy cannot be turned back into mass.
c) A small amount of mass can be turned into a large amount of energy.
d) One kilogram of mass represents 1 joule of energy.
e) It takes a large amount of mass to produce a small amount of energy.

c

The long-term source of energy that powers the Sun is
a) thermal energy of the hydrogen atoms in the Sun.
b) mass energy of hydrogen fusing into helium.
c) chemical potential energy of hydrogen burning into helium.
d) kinetic energy of the orbital motion of the Sun.
e) gravitational potential energy of the contraction of the gas cloud that formed the Sun.

b

Which of the following statements correctly describes the law of conservation of energy?

a) An object always has the same amount of energy.
b) The total quantity of energy in the universe never changes.
c) Energy can change between many different forms, such as potential, kinetic, and thermal, but it is ultimately destroyed.
d) It is not really possible for an object to gain or lose potential energy because energy cannot be destroyed.
e) The fact that you can fuse hydrogen into helium to produce energy means that helium can be turned into hydrogen to produce energy.

b

According to the universal law of gravitation, the force due to gravity is

a) directly proportional to the distance between objects.
b) not dependent on the distance between objects.
c) inversely proportional to the square of the distance between objects.
d) inversely proportional to the distance between objects.
e) directly proportional to the square of the distance between objects.

c

The force of gravity is an inverse square law. This means that, if you double the distance between two large masses, the gravitational force between them

a) is unaffected.
b) weakens by a factor of 4.
c) strengthens by a factor of 4.
d) weakens by a factor of 2.
e) also doubles.

b

According to the universal law of gravitation, if you double the masses of both attracting objects, then the gravitational force between them will

a) decrease by a factor of 4.
b) increase by a factor of 4.
c) not change at all.
d) decrease by a factor of 2.
e) increase by a factor of 2.

b

Suppose you drop a feather and a hammer on the Moon from the same height at the same time. What will happen?

a) They will hit the ground at the same time.
b) The hammer will hit the ground first.
c) They will float in space because of the lack of gravity on the Moon.
d) The feather will hit the ground first.

a

The approximate mass of Jupiter can be calculated by

a) measuring the orbital period and distance of Jupiter’s orbit around the Sun.
b) knowing the Sun’s mass and measuring the average distance of Jupiter from the Sun.
c) measuring the orbital speed of one of Jupiter’s moons.
d) knowing the Sun’s mass and measuring how Jupiter’s speed changes during its elliptical orbit around the Sun.
e) measuring the orbital period and distance of one of Jupiter’s moons

e

Gravity is an inverse square law in distance. Therefore, if the distance between two masses is decreased by a factor of 4, the gravitational force between those two masses

a) decreases by a factor of 4.
b) increases by a factor of 4.
c) increases by a factor of 2.
d) decreases by a factor of 16.
e) increases by a factor of 16.

e

At which lunar phase(s) are tides least pronounced (e.g., the lowest high tides)?

a) new moon
b) full moon
c) first quarter
d) both new and full moons
e) both first and third quarters

e

Newton’s second law states: sum of forces = mass × acceleration. If a known force was applied to an object with a known mass, how would you predict that object’s acceleration?

a) acceleration = sum of forces / mass
b) acceleration = mass × sum of forces
c) acceleration = mass / sum of forces
d) Newton’s second law is irrelevant for solving this problem.

a

The force due to gravity between two objects can be described using the equation Fg = G M1 M2 / d2. In this equation, what does d represent?

a) the universal gravitational constant
b) the distance between the two objects
c) the density of the smaller object

b

The force due to gravity between two objects can be described using the equation Fg = G M1 M2 / d2. In this equation, what does G represent?

a) the density of the smaller object
b) the distance between the two objects
c) the universal gravitational constant

c

He realized the laws of gravity applied to objects in space and on the Earth.

a) Galileo
b) Kepler
c) Copernicus
d) Newton

d

If the Sun instantaneously turned into a black hole of one solar mass, what would happen to the Earth?

a) It would continue to orbit the black hole.
b) It would gradually spiral into the black hole.
c) It would be ejected into outer space.
d) It would be sucked into the black hole

a

As a comet passes by on its closest approach to the Sun, what can we say about how the sum of its potential and kinetic energy has changed since it was at its maximum distance?

a) The sum has increased.
b) The sum has not changed.
c) The sum has decreased.
d) The sum is equal to the universal gravitational constant.

b

Newton’s version of Kepler’s third law states: p2=4π2G(M1+M2)×a3
According to this, what observational information does one need in order to calculate the combined mass of a planet and its moon?

a) the average distance between the two objects and the orbital period
b) the radius of the two planets in meters and the average distance between them
c) the orbital period and the density of the two objects
d) It is impossible to determine the mass of any astronomical object.

a

When is a comet’s orbital angular momentum at its maximum?

a) when the comet is far away from the Sun
b) when the comet is close to the Sun
c) Its angular momentum does not change

c

When is a comet’s orbital speed at its maximum?

a) when it is closest to the Sun
b) when it is farthest from the Sun
c) Its orbital speed does not change.

a

consider the elliptical orbit of a comet around the Sun. Where in its orbit does it have the largest amount of total orbital energy?

a) when it is farthest from the Sun
b) when it is closest to the Sun
c) It always has the same total orbital energy.

c

Consider Earth and the Moon. As you should now realize, the gravitational force that Earth exerts on the Moon is equal and opposite to that which the Moon exerts on Earth. Therefore, according to Newton’s second law of motion __________.

a) the Moon and Earth both have equal accelerations, because the forces are equal
b) Earth has a larger acceleration than the Moon, because it has a larger mass
c) the Moon has a larger acceleration than Earth, because it has a smaller mass

c

What is free-fall, and why does it make you weightless? Briefly describe why astronauts are weightless in the International Space Station.

Free-fall is falling with _______.
Objects in free-fall are weightless because ______
Astronauts in the International Space Station are in ____ free-fall as they fall around Earth (always missing it), so they are weightless.

no resistance to the fall, they are not pushing against anything to give them weight, constant

Compared to their values on Earth, on another planet your

a) mass would be the same but your weight would be different.
b) mass and weight would both be the same.
c) weight would be the same but your mass would be different.

a

The video shows a collapsing cloud of interstellar gas, which is held together by the mutual gravitational attraction of all the atoms and molecules that make up the cloud. As the cloud collapses, the overall force of gravity that draws the cloud inward _______ because __________.

gradually becomes stronger, the strength of gravity follows an inverse square law with distance

As the cloud shrinks in size, its rate of rotation _____ because __________.

speeds up, its total angular momentum is conserved

As the cloud shrinks in size, its central temperature ______ as a result of ______________.

increases, its gravitational potential energy being converted to thermal energy

Suppose that the Sun were to collapse from its current radius of about 700,000 km to a radius of only about 6000 km (about the radius of Earth). What would you expect to happen as a result?

a) A tremendous amount of gravitational potential energy would be converted into other forms of energy, and the Sun would spin much more slowly.
b) The Sun would gain more energy and more angular momentum.
c) A tremendous amount of gravitational potential energy would be converted into other forms of energy, and the Sun would spin much more rapidly.
d) Both the total amount of energy and the rotation rate would remain the same.

c

Suppose that two asteroids are orbiting the Sun on nearly identical orbits, and they happen to pass close enough to each other to have their orbits altered by this gravitational encounter. If one of the asteroids ends up moving to an orbit that is closer to the Sun, what happens to the other asteroid?

a) It will also end up on an orbit that is closer to the Sun.
b) It will end up on an orbit that is farther from the Sun.
c) It will stay on its original orbit.
d) It will become much cooler.

b

As a giant cloud of gas collapses due to gravity, you would expect its rate of rotation to

a) stay unchanged
b) decrease
c) increase

c

Which of the following represents a change from potential energy to kinetic energy?

a) A rock starting from rest on a high cliff, then moving faster and faster as it falls.
b) A kicked ball rising higher in the air and momentarily coming to rest at the top of its trajectory.
c) A car applying its brakes on a straight road and heating up the brake pads as it slows.
d) Sunlight melting a tray of ice.

a

Suppose two objects are attracting each other gravitationally. If you double the distance between them, the strength of their gravitational attraction __________.

a) increases by a factor of 2
b) increases by a factor of 9
c) decreases by a factor of 2
d) increases by a factor of 4
e) decreases by a factor of 9
f) decreases by a factor of 4

f

Which of the following are allowed orbital paths under gravity?
(Select all that apply.)

a) parabolic
b) square
c) elliptical
d) getting sucked in by gravity
e) hyperbolic

a, c, e

Consider the statement "There’s no gravity in space." This statement is:

a) Completely false.
b) False if you are close to a planet or moon, but true in between the planets.
c) Completely true.

a

Earth has two tidal bulges at all times. Approximately where are these bulges located?

a) Both are on lines perpendicular to the Earth-Moon line.
b) One is over the Atlantic Ocean, and one is over the Pacific Ocean.
c) One faces the Moon and one faces the Sun.
d) One faces the Moon and one faces opposite the Moon.

d

Most people are familiar with the rise and fall of ocean tides. Do tides also affect land?

a) Yes, though land rises and falls by a much smaller amount than the oceans.
b) No, tides can only affect liquids and gases, not solids.
c) Yes, land rises and falls with tides equally as high (and low) as the oceans.
d) No, tides only affect the oceans.

a

Any particular location on Earth experiences __________.

a) two sets of high and low tides in the ocean, but only one set on land
b) one high tide and one low tide each day
c) two high tides and two low tides each day
d) two high tides and two low tides each month
e) one high tide and one low tide each month

c

One tidal bulge faces toward the Moon because that is where the gravitational attraction between Earth and the Moon is strongest. Which of the following best explains why there is also a second tidal bulge?

a) The second tidal bulge is a rebound effect, created when water on the side facing the Moon falls back down and thereby pushes up the water on the opposite side of Earth.

b) The second tidal bulge is created by the Sun’s gravity.

c) The second tidal bulge arises because gravity weakens with distance, essentially stretching Earth along the Earth-Moon line.

d) The second tidal bulge is created by the centrifugal force caused by Earth’s rapid rotation.

c

As you watch the video, notice that the size of the tidal bulges varies with the Moon’s phase, which depends on its orbital position relative to the Sun. Which of the following statement(s) accurately describe(s) this variation?
(Select all that apply.)

a) Low tides are highest at full moon and lowest at new moon.
b) High tides are highest at both full moon and new moon.
c) High tides are highest at first- and third-quarter moon.
d) High tides are highest at full moon and lowest at new moon.
e) Low tides are lowest at both full moon and new moon.
f) Low tides are highest at both full moon and new moon.

b, e

You have found that tides on Earth are determined primarily by the position of the Moon, with the Sun playing only a secondary role. Why does the Moon play a greater role in causing tides than the Sun?

a) because the gravitational force between Earth and the Moon is stronger than the gravitational force between Earth and the Sun
b) because the gravitational attraction between Earth and the Moon varies more across Earth than does the gravitational attraction between Earth and the Sun
c) because the Moon orbits Earth faster than Earth orbits the Sun

b

To make a rocket turn left, you need to:

a) fire an engine that shoots out gas to the right.
b) spin the rocket clockwise.
c) fire an engine that shoots out gas to the left.

a

Compared to its angular momentum when it is farthest from the Sun, Earth’s angular momentum when it is nearest to the Sun is

a) greater.
b) less.
c) the same.

c

The difference between speed and velocity is that _________.

a) velocity also includes a direction
b) they are expressed in different units
c) velocity is the same as acceleration but speed is different
d) velocity is calculated using a physics equation

a

Momentum is defined as _________.

a) mass multiplied by acceleration
b) mass multiplied by velocity
c) force multiplied by velocity
d) mass multiplied by speed

b

Suppose you lived on the Moon. Which of the following would be true?

a) Your weight would be less than your weight on Earth, but your mass would be the same as it is on Earth.
b) Both your weight and your mass would be the same as they are on Earth.
c) Your mass would be less than your mass on Earth, but your weight would be the same as it is on Earth.
d) Both your weight and your mass would be less than they are on Earth.

a

Which of the following statements is not one of Newton’s Laws of Motion?

a) What goes up must come down.
b) In the absence of a net force acting upon it, an object moves with constant velocity.
c) The rate of change of momentum of an object is equal to the net force applied to the object.
d) For any force, there always is an equal and opposite reaction force

a

Newton’s Second Law of Motion tells us that the net force applied to an object equals its _________.

a) mass multiplied by velocity
b) momentum multiplied by velocity
c) mass times energy
d) mass multiplied by acceleration

d

Suppose that two objects collide. Which of the following things is not the same both before and after the collision?

a) The total angular momentum of the objects
b) The total momentum of the objects
c) The total energy of the objects
d) The total temperature of the objects

d

The energy attributed to an object by virtue of its motion is known as _________.

a) radiative energy
b) kinetic energy
c) potential energy
d) mass-energy

b

Radiative energy is _________.

a) energy carried by light
b) heat energy
c) energy from nuclear power plants
d) energy of motion

a

Absolute zero is _________.
a) 100° C
b) 0° C
c) 0 Kelvin
d) 0° F

c

What does temperature measure?

a) The total potential energy of particles in a substance
b) The total amount of heat in a substance
c) The average kinetic energy of particles in a substance
d) The average mass of particles in a substance

c

According to the universal law of gravitation, if you triple the distance between two objects, then the gravitational force between them _________.

a) decreases by a factor of 3
b) increases by a factor of 3
c) decreases by a factor of 9
d) increases by a factor of 9

c

What is the difference between a bound orbit and an unbound orbit around the Sun?

a) A bound orbit is circular, whereas an unbound orbit is elliptical.
b) An object on a bound orbit follows the same path around the Sun over and over, whereas an object on an unbound orbit approaches the Sun just once and then never returns.
c) An object on a bound orbit has a gravitational attraction to the Sun, whereas an object on an unbound orbit does not.
d) A bound orbit is an orbit allowed by the universal law of gravitation, and an unbound orbit is not.

b

Why is Newton’s version of Kepler’s third law so useful to astronomers?

a) It can be used to determine the masses of many distant objects.
b) It allows us to calculate distances to distant objects.
c) It explains why objects spin faster when they shrink in size.
d) It tells us that more-distant planets orbit the Sun more slowly

a

What do we mean by the orbital energy of an orbiting object (such as a planet, moon, or satellite)?

a) Orbital energy is the sum of the object’s kinetic energy and its gravitational potential energy as it moves through its orbit.
b) Orbital energy is the object’s kinetic energy as it moves through its orbit.
c) Orbital energy is the amount of energy required for the object to leave orbit and escape into space.
d) Orbital energy is a measure of the object’s speed as it moves through its orbit.

a

Which statement must be true in order for a rocket to travel from Earth to another planet?

a) It must be launched from space, rather than from the ground.
b) It must attain escape velocity from Earth.
c) It must have very large engines.
d) It must carry a lot of extra fuel.

b

Approximately where is it currently high tide on Earth?

a) Anywhere that ocean water laps upon the shore
b) On the portion of Earth facing directly toward the Moon and on the portion of Earth facing directly away from the Moon
c) Wherever it is currently noon
d) Only on the portion of the Earth facing directly toward the Moon

b

Which person is weightless during the activity shown?

the free-falling person

Which of the following statements about the force attracting these two galaxies is true?

a) It is the same force that causes an apple to fall to the ground.
b) The force will get weaker as time passes.
c) It is a mysterious force, whose nature remains completely unknown to scientists.
d) It is a force unlike any force that we ever experience on Earth.

a

The diagram shows a planet at four positions in its orbit. At which position does it have the greatest angular momentum?

a) Position 3
b) Position 4
c) Position 1
d) Position 2
e) The angular momentum is the same at all four points.

e

The diagram shows a planet at four positions in its orbit. At which position does it have the greatest gravitational potential energy?

a) Position 4
b) Position 1
c) Position 3
d) Position 2
e) The gravitational potential energy is the same at all four positions.

c

The diagram shows a planet at four positions in its orbit. At which position does it have the greatest total orbital energy? (Orbital energy , which is the sum of the planet’s kinetic and gravitational potential energy?

a) Position 3
b) Position 1
c) Position 2
d) Position 4
e) The total orbital energy is the same at all four positions.

…

Which of the paths shown represent unbound orbits?

a) Path 2 only
b) Path 1 only
c) Path 3 only
d) Both paths 2 and 3
e) There is no such thing as an unbound orbit.

d

Suppose you are aboard a rocket that is orbiting Earth in the low, circular orbit shown. If you want to escape from Earth and head to the Moon or Mars along the "escape" path shown, what do you need to do?

a) The only way to end up on the "escape" path is to first return to Earth, then launch your rocket with escape velocity.
b) Turn the rocket around, and fire the engine so that you lose speed.
c) Fire the rocket engine in your direction of travel, so that you gain speed.
d) Throw some excess supplies overboard, so that your rocket becomes less massive.

c

Which of the following correctly shows tidal bulges on Earth when the Moon is in the position shown?

two tidal bulges: one facing the Moon and one on the side of Earth opposite to the Moon

In which position(s) of the Moon do we experience the highest high tides?

a) Position 1
b) Position 2
c) Position 3
d) Position 4
e) Positions 1 and 3
f) Positions 2 and 4

e

In which position(s) of the Moon do we experience the lowest low tides?

a) Position 1
b) Position 2
c) Position 3
d) Position 4
e) Positions 1 and 3
f) Positions 2 and 4

e

Which of the following represents a case in which you are not accelerating?

a) driving in a straight line at 60 miles per hour
b) driving 60 miles per hour around a curve
c) slamming on the brakes to come to a stop at a stop sign
d) going from 0 to 60 miles per hour in 10 seconds

a

Why are astronauts weightless in the Space Station?

a) because the Space Station is moving at constant velocity
b) because the Space Station is constantly in free-fall around the Earth
c) because there is no gravity so far from Earth
d) because they are in a vacuum and floating in their spacesuits

b

Suppose you are in an elevator that is traveling upward at constant speed. How does your weight compare to your normal weight on the ground?

a) It is the same.
b) It is less.
c) It is greater.
d) You are weightless.

a

Suppose the Sun were suddenly to shrink in size but that its mass remained the same. According to the law of conservation of angular momentum, what would happen?

a) The Sun would rotate faster than it does now.
b) The Sun’s angular size in our sky would stay the same.
c) The Sun’s rate of rotation would slow.
d) This could never happen, because it is impossible for an e) object to shrink in size without an outside torque.

a

Consider the elliptical orbit of a comet around the Sun. Where in its orbit is the comet moving the fastest?

a) when it is closest to the Sun
b) when it is farthest from the Sun
c) It is always moving at the same speed.

a

A spacecraft requires a propulsion system such as a rocket engine in order to be able to continually move through space.

True or False?

False

By observing the orbital period of a planet’s moon, and measuring the distance between the planet and the moon, one may determine the mass of the moon.

True or False?

True

On a hot day, air particles move around faster than on a cold day.
True or False?

True

As a gas cloud in space shrinks, it

a) spins slower.
b) spins faster.
c) spins at the same rate as it did before it shrank.

b

At which lunar phase(s) are tides most pronounced (for example, the highest high tides)?

a) both new and full moons
b) new moon only
c) full moon only
d) both first and third quarters

a

When NASA’s New Horizons spacecraft passed by Jupiter, its speed increased (but not due to firing its engines). What must have happened?

a) Jupiter’s rotation must have sped up slightly.
b) Jupiter captured an asteroid during the period New Horizons passed by, as accurately predicted in NASA’s mission plan.
c) New Horizons must have dipped through Jupiter’s atmosphere.
d) Jupiter must have lost a very tiny bit of its orbital energy

d

The astronauts feel weightless in the International Space Station, which orbits the Earth once every 90 minutes. Why?

a) because they and the space station are both falling around the Earth
b) because they are moving so fast
c) because the gravity from the Moon cancels out the gravity from Earth
d) because there is no gravity in space

a

Newton showed that Kepler’s laws are ________.

a) the key to proving that Earth orbits our Sun
b) natural consequences of the law of universal gravitation
c) seriously in error
d) actually only three of seven distinct laws of planetary motion

b

Imagine another solar system, with a star more massive than the Sun. Suppose a planet with the same mass as Earth orbits at a distance of 1 AU from the star. How would the planet’s year (orbital period) compare to Earth’s year?

a) The planet’s year would be the same as Earth’s.
b) The planet’s year would be longer than Earth’s.
c) The planet’s year would be shorter than Earth’s.
d) An orbit at a distance of 1 AU would not be possible around a star more massive than the Sun.

c

Imagine another solar system, with a star of the same mass as the Sun. Suppose a planet with a mass twice that of Earth (2MEarth) orbits at a distance of 1 AU from the star. What is the orbital period of this planet?

a) It would not be able to orbit at this distance.
b) 1 year
c) 2 years
d) It cannot be determined from the information given.

b

Suppose you heat an oven to 400°F and boil a pot of water. Which of the following explains why you would be burned by sticking your hand briefly in the pot but not by sticking your hand briefly in the oven?

a) The oven has a higher temperature than the water.
b) The molecules in the water are moving faster than the molecules in the oven.
c) The water has a higher temperature than the oven.
d) The water can transfer heat to your arm more quickly than the air due to its density

d

Suppose you kick a soccer ball straight up to a height of 10 meters. Which of the following is true about the gravitational potential energy of the ball during its flight?

a) The ball’s gravitational potential energy is greatest at the instant it returns to hit the ground.
b) The ball’s gravitational potential energy is greatest at the instant when the ball is at its highest point.
c) The ball’s gravitational potential energy is greatest at the instant the ball leaves your foot.
d) The ball’s gravitational potential energy is always the same.

b

A planet is orbiting a star. Which of the following statements is true for the acceleration and gravitational forces experienced by the star and the planet?

a) The force on the star is much smaller than the force on the planet, but the accelerations are about equal.
b) The acceleration of the planet is much more than the acceleration of the star, but the force on the star is the same but opposite the force on the planet.
c) The acceleration of the planet is much more than the acceleration of the star, and the force on the planet is much more than the force on the star

b

Which of the following examples describes a situation where a car is experiencing a net force?

a) The car is floating on a stationary boat.
b) The car is moving at constant speed.
c) The car is making a gradual turn.
d) The car is stopped on a hill.

c

The Moon is constantly falling toward Earth.
True or False?

True

When energy is converted from one form to another, a tiny amount is inevitably lost.
True or False?

False

The acceleration of gravity on Earth is approximately 10 m/s2 (more precisely, 9.8 m/s2). If you drop a rock from a tall building, about how fast will it be falling after 3 seconds?

a) 30 m/s
b) 20 m/s
c) 30 m/s2
d) 10 m/s2
e) 10 m/s

a

Suppose you lived on the Moon. Which of the following would be true?

a) Your weight would be less than your weight on Earth, but your mass would be the same as it is on Earth.
b) Both your weight and your mass would be less than they are on Earth.
c) Your mass would be less than your mass on Earth, but your weight would be the same as it is on Earth.
d) Both your weight and your mass would be the same as they are on Earth

a

The difference between speed and velocity is that ________.

a) velocity also includes a direction
b) velocity is calculated using a physics equation
c) velocity is the same as acceleration but speed is different
d) they are expressed in different units

a

In which of the following cases would you feel weightless?

a) while walking on the Moon
b) while accelerating downward in an elevator
c) while parachuting from an airplane
d) while falling from a roof

d

When a spinning ice skater pulls in his arms, he spins faster because ________.

a) there is less friction with the ice
b) there exists an unbalanced reaction force
c) his angular momentum must be conserved, so reducing his radius must increase his speed of rotation
d) there is less friction with the air

c

If one drops a golf ball and a bowling ball simultaneously from the same height above the ground, what will happen? Neglect the effects of wind or air resistance.

a) The golf ball and the bowling ball will hit the ground at the same time.
b) The golf ball will hit the ground before the bowling ball.
c) The bowling ball will hit the ground before the golf ball.

a

What does temperature measure?

a) the average mass of particles in a substance
b) the amount of infrared radiation emitted by an object
c) the average kinetic energy of particles in a substance
d) the total potential energy of particles in a substance

c

In the formula E = mc2, what does E represent?

a) the kinetic energy, also known as Einsteinium
b) the gravitational potential energy of an object held above the ground
c) the radiative energy carried by light
d) the electric field produced by a charge
e) the mass-energy, or potential energy stored in an object’s mass

e

Consider a star with 2 planets. The mass of planet A is the same as the mass of planet B. The orbit of Planet A is on average, closer to the star than the orbit of Planet B. Which of the following statements is true?

a) Planet A moves with the same speed as Planet B.
b) Planet A is moving slower than Planet B.
c) Planet A is moving faster than Planet B.
d) The relative orbital speeds depend on the masses of the planets.

c

Consider the gravitational force between the Sun and Earth. Which of the following statements describes the situation the best?

a) The gravitational force experienced by the Sun is equal and opposite to the gravitational force experienced by the Earth.
b) The acceleration experienced by the Sun due to the Earth is equal and opposite to the acceleration experienced by the Earth due to the Sun.
c) Both of these statements are true.

a

What is the acceleration of gravity at the surface of Earth?

a) 9.8 km/s2 downward
b) 9.8 m/s downward
c) 9.8 m2/s downward
d) 9.8 m/s2 downward
e) 9.8 km/s downward

d

There is no gravity in space.

True or False?

False

Moving two objects 10 times closer to each other will increase their gravitational attraction 100 times.

True or False?

True

Tidal friction caused by Earth’s stretching from the Moon’s gravity is gradually slowing down the rotation of Earth.

True or False?

True

The Moon is slowly moving away from Earth.

True or False?

True

When you experience a downward gravitational force from Earth, Earth likewise experiences an upward gravitational force from you. The second force will be substantially weaker.

True or False?

False

Earth’s tidal forces acting on the Moon have caused one side of the Moon to be constantly facing Earth.

True or False?

True

In consideration of tidal forces on the earth-Moon system, we find

a) The Moon exerts tidal forces on the Earth
b) The sun exerts tidal forces on both the Earth and the Moon but these are much weaker than what they exert on each other.
c) The Earth exerts tidal forces on the Moon
d) all of the above

d

We only see one face of the Moon from Earth because

a) It is because the Moon does not rotate as it orbits.
b) The Moon is already tidally locked to the Earth.
c) It just happened by chance.

b

Part A – Tidal forces on Earth are causing

a) The Earth to speed up its rotation rate
b) the EArth to orbit the Sun faster.
c) the Earth to orbit the Sun slower
d) the Earth to slow down its rotation rate

d

In a vacuum, the various forms of light (all the types of electromagnet waves) always travel at one speed, the speed of light, while electrons, neutrons, protons, and atoms can travel over distances at any lower speed.
True or False?

True

You are currently emitting electromagnetic waves.
True or False?

True

Electrons always travel at the speed of light.
True or False?

False

X-rays, because they have more energy, travel through space faster than visible light.
True or False?

False

The greater the wavelength of light, the greater its energy.
True or False?

False

The shorter the wavelength of light, the higher its frequency.
True or False?

True

Grass is green because it absorbs green light, reflecting all other colors.
True or False?

False

Electrons orbit an atomic nucleus like planets orbit the Sun.
True or False?

False

The atomic nuclei of the same element always have the same number of protons.
True or False?

True

Atomic nuclei consist of protons, electrons, and neutrons.
True or False?

False

Which object is likely to be the coldest? The object whose light spectrum is brightest in the

a) infrared.
b) visible light.
c) ultraviolet.
d) X-rays.

d

When an electron drops to a lower energy level in an atom,

a) light at a wavelength specific to the change in energy levels is emitted.
b) the electron becomes more massive.
c) the atom moves more slowly.
d) the extra energy disappears.

a

An atomic nucleus has a size of about,

a) 10ˆ-6 meters.
b) 10ˆ-12 meters.
c) 10ˆ-9 meters.
d) 10ˆ-15 meters.

d

A typical atom has a size of about

a) 0.1 millimeters (10-4 meters).
b) 0.1 micrometers (10-7 meters).
c) 0.1 nanometers (10-10 meters).
d) 0.1 picometers (10-13 meters).

c

Which is the longest wavelength?

a) 10 nm
b) 10 cm
c) 10 km
d) 10 m

c

Consider an atom of zinc in which the nucleus contains 30 protons and 35 neutrons. What is its atomic number and atomic mass number?

a) The atomic number is 35, and the atomic mass number is 30.
b) The atomic number is 35, and the atomic mass number is 65.
c) The atomic number is 30, and the atomic mass number is 65.
d) The atomic number is 30, and the atomic mass number is 35.

c

From lowest energy to highest energy, which of the following correctly orders the different categories of electromagnetic radiation?

a) gamma rays, X-rays, visible light, ultraviolet, infrared, radio
b) radio, X-rays, visible light, ultraviolet, infrared, gamma rays
c) radio, infrared, visible light, ultraviolet, X-rays, gamma rays
d) infrared, visible light, ultraviolet, X-rays, gamma rays, radio
e) visible light, infrared, X-rays, ultraviolet, gamma rays, radio

c

How are wavelength, frequency, and energy related for photons of light?

a) Longer wavelength means higher frequency and lower energy.
b) Longer wavelength means lower frequency and lower energy.
c) Longer wavelength means lower frequency and higher energy.
d) Longer wavelength means higher frequency and higher energy.
e) There is no simple relationship because different photons travel at different speeds.

b

The wavelength of a wave is

a) the distance between a peak of the wave and the next trough.
b) how strong the wave is.
c) equal to the speed of the wave times the wave’s frequency.
d) the distance between two adjacent peaks of the wave.
e) the distance between where the wave is emitted and where it is absorbed.

d

Which statement about photons of light is true?

a) An infrared photon has more energy than an X-ray photon, but travels at the same speed.
b) An infrared photon has less energy than an X-ray photon, and travels more slowly.
c) An infrared photon has more energy than an X-ray photon, and travels more quickly.
d) An infrared photon has less energy than an X-ray photon, but travels at the same speed.

d

Which of the following best describes the fundamental difference between two different chemical elements (such as oxygen and carbon)?

a) They have different names.
b) They have different atomic mass numbers.
c) They have different numbers of protons in their nucleus.
d) They have different numbers of electrons.

c

Suppose you know the frequency of a photon and the speed of light. What else can you determine about the photon?

a) its wavelength and energy
b) its acceleration
c) its temperature
d) the chemical composition of the object that emitted it

a

Cell phone signals passing through walls is an example of

a) reflection or scattering.
b) transmission.
c) emission.
d) absorption.

b

Blue light hitting a red sweatshirt is an example of

a) reflection or scattering.
b) emission.
c) absorption.
d) transmission

c

From shortest to longest wavelength, which of the following correctly orders the different categories of electromagnetic radiation?

a) gamma rays, X-rays, ultraviolet, visible light, infrared, radio
b) infrared, visible light, ultraviolet, X-rays, gamma rays, radio
c) gamma rays, X-rays, visible light, ultraviolet, infrared, radio
d) radio, infrared, visible light, ultraviolet, X-rays, gamma rays

a

Which forms of light are lower in energy and frequency than the light that our eyes can see?

a) Ultraviolet and X-rays
b) Visible light
c) Infrared and radio
d) Infrared and ultraviolet

c

When considering light as made up of individual "pieces," each characterized by a particular amount of energy, the pieces are called _________.

a) gamma rays
b) photons
c) wavicles
d) frequencies

b

Suppose you built a scale-model atom in which the nucleus is the size of a tennis ball. About how far would the cloud of electrons extend?

a) To the Sun
b) Several centimeters
c) A few meters
d) Several kilometers

d

Consider an atom of carbon in which the nucleus contains 6 protons and 7 neutrons. What is its atomic number and atomic mass number?

a) atomic number = 6; atomic mass number = 7
b) atomic number = 13; atomic mass number = 6
c) atomic number = 7; atomic mass number = 13
d) atomic number = 6; atomic mass number = 13

d

If we say that a material is opaque to ultraviolet light, we mean that it _________.

a) absorbs ultraviolet light
b) reflects ultraviolet light
c) transmits ultraviolet light
d) emits ultraviolet light

a

Suppose you look at a detailed spectrum of visible light from some object. How can you decide whether it is an emission line spectrum or an absorption line spectrum?

a) An emission line spectrum consists of a long bright line, while an absorption line spectrum consists of a long dark line.
b) The emission line spectrum is produced by electrons jumping up in energy level, while the absorption line spectrum is produced by electrons jumping down in energy level.
c) The only way to decide is to make a graph of the intensity of the light at every wavelength, and then analyze the graph carefully.
d) An emission line spectrum consists of bright lines on a dark background, while an absorption line spectrum consists of dark lines on a rainbow background.

d

An atom that has fewer electrons than protons is called a(n) _________.

a) molecule
b) plasma
c) ion
d) solid

c

Thermal radiation is defined as _________.

a) radiation that is felt as heat
b) radiation with a spectrum whose shape depends only on the temperature of the emitting object
c) radiation produced by an extremely hot object
d) radiation in the form of emission lines from an object

b

According to the laws of thermal radiation, hotter objects emit photons with _________.

a) a shorter average wavelength
b) a lower average energy
c) a lower average frequency
d) a higher average speed

a

Suppose you want to know the chemical composition of a distant star. Which piece of information is most useful to you?

a) The wavelengths of spectral lines in the star’s spectrum
b) Whether the star’s spectrum has more emission lines or more absorption lines
c) The peak energy of the star’s thermal radiation
d) The Doppler shift of the star’s spectrum

a

The spectra of most galaxies show redshifts. This means that their spectral lines _________.

a) have a higher intensity in the red part of the spectrum
b) have wavelengths that are shorter than normal
c) have wavelengths that are longer than normal
d) always are in the red part of the visible spectrum

c

What does angular resolution measure?

a) The size of an image.
b) The angular size of the smallest features that the telescope can see.
c) The number of electromagnetic waves captured by an image.
d) The brightness of an image.

b

Which of the following statements best describes the two principle advantages of telescopes over eyes?

a) Telescopes can collect far more light with far better angular resolution.
b) Telescopes can collect far more light with far greater magnification.
c) Telescopes have much more magnification and better angular resolution.
d) Telescopes collect more light and are unaffected by twinkling.

a

What is the purpose of interferometry?

a) It reduces the twinkling of stars caused by atmospheric turbulence.
b) It is designed to prevent light pollution from interfering with astronomical observations.
c) It allows two or more small telescopes to achieve the angular resolution of a much larger telescope.
d) It allows two or more small telescopes to achieve a larger light-collecting area than they would have independently.

c

What do astronomers mean by light pollution?

a) Light pollution is a term used to describe the appearance of the sky in regions that are crowded with stars.
b) Light pollution is a type of air pollution created by lightweight gases such as hydrogen and helium.
c) Light pollution means contamination of light caused by chemicals in the Earth’s atmosphere.
d) Light pollution is light from human sources that makes it difficult to see the stars at night.

d

The stars in our sky twinkle in brightness and color because of _________.

a) light pollution
b) the bubbling and boiling of gases on the surfaces of stars
c) rapid changes in the brightnesses and colors of stars caused by changes in their spectra
d) turbulence in the Earth’s atmosphere

d

What is the purpose of adaptive optics?

a) It allows ground-based telescopes to observe ultraviolet light that normally does not penetrate the atmosphere.
b) It allows several small telescopes to work together like a single larger telescope.
c) It reduces blurring caused by atmospheric turbulence for telescopes on the ground.
d) It is a special technology that allows the Hubble Space Telescope to adapt to study many different types of astronomical objects.

c

Suppose you watch a leaf bobbing up and down as ripples pass it by in a pond. You notice that it does two full up and down bobs each second. Which statement is true of the ripples on the pond?

a) We can calculate the wavelength of the ripples from their frequency.
b) They have a wavelength of two cycles per second.
c) They have a frequency of 4 hertz.
d) They have a frequency of 2 hertz.

d

Which of the following best describes why we say that light is an electromagnetic wave?

a) Light can be produced only by electric or magnetic appliances.
b) The passage of a light wave can cause electrically charged particles to move up and down.
c) Light is produced only when massive fields of electric and magnetic energy collide with one another.
d) The term electromagnetic wave arose for historical reasons, but we now know that light has nothing to do with either electricity or magnetism.

b

Which of the following statements about X-rays and radio waves is not true?

a) X-rays have shorter wavelengths than radio waves.
b) X-rays have higher frequency than radio waves.
c) X-rays travel through space faster than radio waves.
d) X-rays and radio waves are both forms of light, or electromagnetic radiation.

c

Each of the following describes an "Atom 1" and an "Atom 2." In which case are the two atoms different isotopes of the same element?

a) Atom 1: nucleus with 7 protons and 8 neutrons, surrounded by 7 electrons; Atom 2: nucleus with 7 protons and 7 neutrons, surrounded by 7 electrons
b) Atom 1: nucleus with 8 protons and 8 neutrons, surrounded by 8 electrons; Atom 2: nucleus with 8 protons and 8 neutrons, surrounded by 7 electrons
c) Atom 1: nucleus with 4 protons and 5 neutrons, surrounded by 4 electrons; Atom 2: nucleus with 5 protons and 5 neutrons, surrounded by 4 electrons
d) Atom 1: nucleus with 6 protons and 8 neutrons, surrounded by 6 electrons; Atom 2: nucleus with 7 protons and 8 neutrons, surrounded by 7 electrons

a

Which of the following statements is true of green grass?

a) It means the lawn is healthy.
b) It absorbs red light and reflects green light.
c) It transmits all colors of light except green.
d) It absorbs red light and emits green light.

b

Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space?

a) The cloud is extremely hot.
b) The cloud is visible primarily because it reflects light from nearby stars.
c) The cloud is cool and very dense, so that you cannot see any objects that lie behind it.
d) The cloud is cool and lies between you and a hot star.

…

Which of the following statements about thermal radiation is always true?

a) A hot object emits more radiation per unit surface area than a cool object.
b) A hot object produces more total infrared emission than a cooler object.
c) All the light emitted by hot object has higher energy than the light emitted by a cooler object.
d) A cold object produces more total infrared and radio emission per unit surface area than a hot object.

a

Betelgeuse is the bright red star representing the left shoulder of the constellation Orion. All the following statements about Betelgeuse are true. Which one can you infer from its red color?

a) It is moving away from us.
b) It is much brighter than the Sun.
c) It is much more massive than the Sun.
d) Its surface is cooler than the surface of the Sun.

d

Laboratory measurements show hydrogen produces a spectral line at a wavelength of 486.1 nanometers (nm). A particular star’s spectrum shows the same hydrogen line at a wavelength of 486.0 nm. What can we conclude?

a) The star is getting hotter.
b) The star is moving toward us.
c) The star is getting colder.
d) The star is moving away from us.

b

Suppose that Star X and Star Y both have redshifts, but Star X has a larger redshift than Star Y. What can you conclude?

a) Star Y is moving away from us faster than Star X.
b) Star X is hotter than Star Y.
c) Star X is coming toward us faster than Star Y.
d) Star X is moving away from us and Star Y is moving toward us.
e) Star X is moving away from us faster than Star Y.

e

Studying a spectrum from a star can tell us a lot. All of the following statements are true except one. Which statement is not true?

a) The peak of the star’s thermal emission tells us its temperature: hotter stars peak at shorter (bluer) wavelengths.
b) Shifts in the wavelengths of spectral lines compared to the wavelengths of those same lines measured in a laboratory on Earth can tell us the star’s speed toward or away from us.
c) The total amount of light in the spectrum tells us the star’s radius.
d) We can identify chemical elements present in the star by recognizing patterns of spectral lines that correspond to particular chemicals.

c

The angular separation of two stars is 0.1 arcseconds, and you photograph them with a telescope that has an angular resolution of 1 arcsecond. What will you see?

a) The photo will seem to show only one star rather than two.
b) You will see two distinct stars in your photograph.
c) The stars will not show up at all in your photograph.
d) The two stars will appear to be touching, looking rather like a small dumbbell.

a

How does the light-collecting area of an 8-meter telescope compare to that of a 2-meter telescope?

a) The 8-meter telescope has 16 times the light-collecting area of the 2-meter telescope.
b) The answer cannot be determined from the information given in the question.
c) The 8-meter telescope has 4 times the light-collecting area of the 2-meter telescope.
d) The 8-meter telescope has 8 times the light-collecting area of the 2-meter telescope.

a

Which of the following is not an advantage of the Hubble Space Telescope over ground-based telescopes?

a) It is closer to the stars.
b) Stars do not twinkle when observed from space.
c) It never has to close because of cloudy skies.
d) It can observe infrared and ultraviolet light, as well as visible light.

a

The Chandra X-ray Observatory must operate in space because ______________________.

a) It was built by NASA
b) X-ray telescopes require the use of grazing incidence mirrors
c) X-rays do not penetrate Earth’s atmosphere
d) X-rays are too dangerous to be allowed on the ground

c

Which of the following is always true about images captured with X-ray telescopes?

a) They always have high angular resolution.
b) They are always shown with colors that are not the true colors of the objects that were photographed.
c) They are always very pretty.
d) They show us light with extremely long wavelengths compared to the wavelengths of visible light.
e) They always are made with adaptive optics.

b

Why are astronomers interested in building observatories capable of detecting neutrinos, cosmic rays, and gravitational waves?

a) These things are not forms of light, and therefore can provide different types of information than light about objects that emit them.
b) These things are emitted from the same objects that emit X-rays, but unlike X-rays they can be detected with observatories on the ground.
c) These things should in principle be much easier to detect than light, which means we could build these observatories cheaply.
d) These things are the highest energy forms of light, even more energetic than gamma rays, and therefore can tell us about explosive processes in the universe.

a

How much better is a 10-meter diameter mirror than a 5-meter diameter mirror, in a space telescope for visible/optical light?

a) 2 times more collecting area, 2 times better angular resolution.
b) 4 times more collecting area, 2 times better angular resolution.
c) 4 times more collecting area, 4 times better angular resolution.
d) Telescope mirror size doesn’t matter.

b