Astronomy 101 Thought Questions - Fall 2015

## Thought Questions for Astronomy 101 (Fall 2015) Instructor: Eric Sandquist

### Question Topics:

 Compass Directions Seasons Planet Motions in the Sky Motion and Newton's Laws Rising and Setting Moon Phases Kepler's Laws Gravity Time of Day Eclipses Models of the Universe Light

## Compass Directions

If you are standing on Earth and facing due south, which of the following is true?

1. East is to your left and west is to your right.
2. West is to your left and east is to your right.
3. Neither of the above can be true.

Imagine you are looking down on the Earth from out in space. For a person standing at the place marked "X" north of the equator, what is the correct orientation of the directions?

Imagine you are looking down on Earth's North Pole from out in space. For a person standing at the place marked "X", what is the correct orientation of the directions?

Imagine you are looking down on Earth's North Pole from out in space. For a person standing at the place marked "X", what is the correct orientations of the directions?

Which direction does the person have to look to see the star shown below?

1. North
2. South
3. East
4. West
5. None of the above

In what direction should you face to see this star when it is highest in the sky?

1. Toward the north
2. Toward the south
3. Toward the east
4. Toward the west
5. Directly overhead

## Rising and Setting

This is what the sky would look like at noon on a given day. Where would you expect the Sun to be located at sunset?

1. On the horizon to the east.
2. On the horizon to the west.
3. On the horizon to the south.
4. On the horizon to the north.

If you could see stars during the day, this is what the sky would look like at noon on a given day. The Sun is near the stars of the constellation Gemini. Near which constellation would you expect the Sun to be located at sunset?

1. Leo
2. Cancer
3. Gemini
4. Taurus
5. Pisces

If you are standing at the North Pole, how would stars appear to move around the sky?

1. Stars would rise in the east and set in the west.
2. Stars would remain stationary in the sky.
3. Stars would move in circles around the sky parallel to the horizon.

If you are standing on the equator and looking east, stars will appear to move...

1. from right to left (south to north).
2. from left to right (north to south).
3. straight up from the horizon.
4. straight down toward the horizon.

If you look due north from San Diego, which picture shows how stars would move across the sky during a night? (Remember the North Star.)

Stars that never appear to set are called circumpolar. As you move from Earth's equator toward the North Pole, the number of stars that are circumpolar

1. increases.
2. decreases.
3. stays the same.

## Time of Day

For the person at position B, what direction would he have to look to see the Sun on the horizon?

1. North
2. South
3. East
4. West

For the person at position B in the diagram above, roughly what time of day must it be?

1. Noon
2. 6 pm
3. Midnight
4. 6 am

Looking down on the Earth from above the North Pole, the Earth will

1. rotate clockwise.
2. rotate counterclockwise.
3. not rotate clockwise or counterclockwise.

About what time of day would it appear to be for the person shown?

1. 6 am
2. 12 noon
3. 6 pm
4. 12 midnight

About what time of day would it appear to be for the person shown? ("NP" is the North Pole.)

1. 2 pm
2. 9 am
3. 6 am
4. 3 am
5. 9 pm

## Seasons

On January 21st, which constellation is behind the Sun?

1. Gemini
2. Cancer
3. Leo
4. Aquarius
5. Capricornus
6. Sagittarius

On November 21st, which constellation will be on the opposite side of the sky from the Sun?

1. Aries
2. Virgo
3. Libra
4. Scorpius
5. Pisces
6. Taurus

Which of the people shown would see the Sun as being highest overhead?

1. Person 1
2. Person 2
3. Person 3
4. Person 4
5. Person 5

In the diagram above, what season is it for person 1 in the northern hemisphere?

1. Fall
2. Summer
3. Spring
4. Winter

Which of the following statements about the location of the Sun at sunrise in the middle of winter is true?

1. The Sun will rise north of east.
2. The Sun will rise directly in the east.
3. The Sun will rise south of east.
4. None of the above.

As seen from your current location, when will an upright flagpole cast NO shadow (because the Sun is directly above the flagpole)?

1. Every day at noon.
2. Only on the first day of summer.
3. Only on the first day of winter.
4. On the first days of spring and fall.
5. Never from your current location.

If the Sun is high in the sky to the southeast, what will the shadow of a stick be like?

1. Short, pointing SE
2. Short, pointing NE
3. Short, pointing NW
4. Short, pointing NE
5. Long, pointing SE
6. Long, pointing NE
7. Long, pointing NW
8. Long, pointing SW

In the diagrams below, the light raws are equal distances from each other. Which of the people shown would collect the most sunlight each second?

1. Person A
2. Person B
3. Person C
4. The collect the same amount because they are the same size.

If it is summertime right now, how does the altitude of the noontime Sun change (if at all) as winter approaches?

1. It increases.
2. It decreases.
3. It stays the same.

The diagram below show possible ways of setting up Earth's orbit and Earth's rotation axis. In the two cases, would the Sun appear to change in size during a year?

1. Hypothesis 1: no; Hypothesis 2: yes
2. Hypothesis 1: no; Hypothesis 2: no
3. Hypothesis 1: yes; Hypothesis 2: yes
4. Hypothesis 1: yes; Hypothesis 2: no

The diagram above show possible ways of setting up Earth's orbit and Earth's rotation axis. In the two cases, what season would it be in the souther hemisphere if it is summer in the northern hemisphere?

1. Hypothesis 1: winter; Hypothesis 2: winter
2. Hypothesis 1: winter; Hypothesis 2: summer
3. Hypothesis 1: summer; Hypothesis 2: summer
4. Hypothesis 1: summer; Hypothesis 2: winter

Imagine the picture below shows the view of Earth from the Sun. To someone in the northern hemisphere, what would day and night be like?

1. The Sun would be above the horizon for more than half of the day.
2. The Sun would be above the horizon for less than half of the day.
3. The Sun would be above the horizon for exactly half of the day.

Imagine the picture below shows two views of Earth from the Sun. To someone in the northern hemisphere, when would the Sun be higher in the sky at noontime?

1. The noontime Sun would be higher in the sky for the day shown in picture A.
2. The noontime Sun would be higher in the sky for the day shown in picture B.
3. The noontime Sun would get equally high in the sky in both pictures.

The pictures on the right side of the diagram below show views of the Earth from the Sun. Which one corresponds to summer in the southern hemisphere?

If the Earth is oriented as shown in the diagram, are there places where it will be dark for more than 24 hours at a time?

1. Yes - near the North Pole.
2. Yes - on the Equator.
3. Yes - on the side of the Earth facing away from the Sun.
4. Yes - near the South Pole.
5. No - everywhere will receive at least some sunlight.

What would seasons be like on the planet shown below?

1. There would be seasons, but the temperature changes would be more extreme than Earth's seasons.
2. The seasons would be just like those on Earth.
3. There would be seasons, but the temperature changes would be less noticeable than Earth's seasons.
4. There would not be any seasons on this planet.

## Moon Phases

For more practice, see the Lunar Phase Quizzer animation.

The diagram below shows Earth and the Sun as well as 5 different possible positions of the Moon. Which position of the Moon best corresponds with the phase of the Moon shown in the box?

If the Moon looked like this from Earth, what would you see if you looked at the exact opposite side of the Moon?

How much of the Moon's entire surface is illuminated by the Sun during the phase shown in the box above?

1. None of the surface is illuminated.
2. Less than half of the surface is illuminated.
3. Half of the surface is illuminated.
4. More than half of the surface is illuminated.
5. All of the surface is illuminated.

How much of the Moon's illuminated surface is visible from Earth during the phase shown in the box above?

1. None of the surface (visible from Earth) is illuminated.
2. Less than half of the surface (visible from Earth) is illuminated.
3. Half of the surface (visible from Earth) is illuminated.
4. More than half of the surface (visible from Earth) is illuminated.
5. All of the surface (visible from Earth) is illuminated.

The diagram below shows Earth and the Sun as well as 5 different possible positions of the Moon. Which position of the Moon best corresponds with the phase of the Moon shown in the box?

How much of the Moon's illuminated surface is visible from Earth during the phase shown in the box above?

1. None of the surface (visible from Earth) is illuminated.
2. Less than half of the surface (visible from Earth) is illuminated.
3. Half of the surface (visible from Earth) is illuminated.
4. More than half of the surface (visible from Earth) is illuminated.
5. All of the surface (visible from Earth) is illuminated.

What does the Moon's phase look like from the northern hemisphere of Earth (the part of Earth facing you in the figure below)?

What would the Moon's phase look like from the northern hemisphere of Earth (the part of Earth facing you in the figure below)?

For a person on Earth, at what time would the Moon be highest overhead when the Moon is at the position shown?

1. Noon
2. 6 pm
3. Midnight
4. 6 am
5. None of the above

If the Moon is positioned as shown below, about what time would it be overhead?

1. 9 am
2. 3 pm
3. 9 pm
4. 3 am
5. None of the above

If the Moon is positioned in its orbit as shown below, at what time would it be highest overhead?

1. 9 am
2. 3 pm
3. 9 pm
4. 3 am
5. None of the above

If the Moon is positioned as shown below, about what time would the Moon rise?

1. Sunset
2. Midnight
3. Sunrise
4. Noon
5. None of the above

If the Moon is positioned as shown below, about what time would the Moon set?

1. 9 pm
2. 3 am
3. 9 am
4. 3 pm
5. None of the above

What is the phase of the Moon when it is in the position shown above?

1. waxing crescent
2. waxing gibbous
3. waning gibbous
4. waning crescent

Which phase of the Moon rises in the east as the Sun rises in the east?

1. first quarter
2. full
3. third quarter
4. new

What would the Moon's phase look like if it was in the position shown?

Many people incorrectly believe that Earth's shadow causes Moon phases. If this incorrect belief were true, then which location would produce the Moon phases shown in the upper right corner of the figure below?

## Eclipses

If we make the Earth the size of a basketball (12 in. across), then if the Moon is also made the same scale, it should be about 3 in. across. How far from Earth should the Moon be on this scale?

1. 2 inches away
2. 1 foot away
3. 4 feet away
4. 30 feet away
5. 300 feet away

What does the Moon's phase have to be if there is a solar eclipse?

1. new
2. first quarter
3. full
4. third quarter
5. It can happen in any phase.

What phase does the Moon have to be for there to be a lunar eclipse?

1. new
2. first quarter
3. full
4. third quarter

At what times is it possible to see a lunar eclipse from Earth?

1. Any time during nighttime.
2. Any time during daytime.
3. Only at midnight.
4. Only at noon.
5. Only at sunrise.
6. Only at sunset.

Match the appearance of the solar eclipse (the numbered choices) with the place you would have to be to see it (the letters) in the figure below.

What would the Moon look like (from Earth) when it is at the positions (A and B) shown?

An observer on Earth sees a total lunar eclipse. At the same time, if someone is standing on the Moon facing the Earth, what would they see?

1. Earth's night side, not eclipsing the Sun
2. Earth's day side, not eclipsing the Sun
3. Earth partially eclipsing the Sun
4. Earth totally eclipsing the Sun

## Planet Motions in the Sky

If you carefully watch over several nights, how will the Moon appear to move compared to stars in constellations?

1. From east to west.
2. From west to east.
3. The Moon doesn't appear to move over several nights.

Where would you look to see a planet rise when it is in retrograde motion?

1. Near the eastern horizon.
2. Near the western horizon.

A planet moving in retrograde motion will, over the course of one night, appear to

1. move east to west.
2. move west to east.
3. not move at all, as planets do not move with the stars.
4. move randomly, as planets move differently than the stars.

A planet is moving in retrograde motion. Over the course of several nights, how will the planet appear to move relative to the background stars?

1. move east to west.
2. move west to east.
3. It will not move at all, as planets do not move with the stars.
4. It will move randomly, as planets move differently than the stars.

If Venus and the Sun are on separate merry-go-rounds, but both are making one circle of the Earth in exactly the same amount of time, what would we see from Earth over time?

1. Venus would at first appear to move closer to the Sun.
2. Venus and the Sun would move together, always in the same positions relative to each other.
3. Venus would at first appear to move farther away from the Sun.
4. Venus would stay near the Sun, but would appear to circle around it.

If Venus and the Sun are on separate merry-go-rounds (as pictured in the previous question), but Venus' merry-go-round makes one circle of the Earth in slightly less time than the Sun's merry-go-round does, what would we see from Earth over time?

1. Venus would at first appear to move closer to the Sun.
2. Venus and the Sun would move together, always in the same positions relative to each other.
3. Venus would at first appear to move farther away from the Sun.
4. Venus would stay near the Sun, but would appear to circle around it.

In the heliocentric model shown below, where would a planet have to be to be seen overhead by a person at midnight on Earth?

In the picture above, at roughly what time would the planet at position 5 be roughly overhead (high above the horizon)? (Earth rotates counterclockwise from this point of view.)

1. 3 am.
2. 9 am.
3. 3 pm.
4. 9 pm.
5. It is not possible to tell from the diagram.

The picture shows the solar system today. Which planet will be highest overhead at around midnight?

1. Jupiter (J)
2. Mars (M)
3. Pluto (P)
4. Saturn (S)
5. Uranus (U)

The picture shows the inner solar system today. When would Venus (V) be highest overhead? (Earth rotates counterclockwise in this view.)

1. Late morning (6 am - noon)
2. Afternoon (Noon - 6 pm)
3. Evening (6 pm - midnight)
4. Early morning (Midnight - 6 am)

If you lived on Venus and you monitored Earth's position in the sky over the course of several years, what would you see?

1. Earth always moves from east to west relative to the stars.
2. Earth always moves from west to east relative to the stars.
3. Earth usually move from west to east relative to the stars, but would occasionally undergo retrograde motion (east to west).
4. Earth is always fairly close to the Sun in the sky, and is most easily visible before sunrise or after sunset.

If you lived on another planet and you watched Earth's position in the constellations over the course of several years, which ones would see Earth do retrograde motion? (Give all correct answers.)

1. Mercury
2. Venus
3. Mars
4. Jupiter
5. Saturn

## Kepler's Laws

NASA wants to launch a spaceship from Earth (inner circle) to Mars (outer circle) and immediately come back. Which of the pictured orbits is possible according to Kepler's first law?

Mars moves in an elliptical orbit around the Sun. The location of the Sun relative to this ellipse is

1. at the focus which is closer to the point where Mars is moving the slowest.
2. at the focus which is closer to the point where Mars is moving the fastest.
3. at the center of the ellipse.
4. at one end of the longer axis of the ellipse.
5. at one end of the shorter axis of the ellipse.

The picture below shows the orbit of a planet around the Sun with the planet in different positions. Rank the planet's speed when it is at the different positions in order from fastest to slowest.

1. Z > V > Y > W > X
2. X > W > Y > V > Z
3. Z > Y > X > W > V
4. X > Y > Z > V > W
5. V > W > X > Y > Z

The Earth is a few percent closer to the Sun in January than it is in July. What does this fact mean for the lengths of the seasons?

1. Winter in the northern hemisphere will be a few days longer than summer.
2. Summer in the northern hemisphere will be a few days longer than winter.
3. This does not change the fact that the seasons are all of equal length.

If a small weather satellite and the large International Space Station are orbiting Earth at the same altitude above Earth's surface, which object takes longer to orbit once around Earth?

1. The large space station.
2. The small weather satellite
3. They would take the same amount of time.

NASA wants to launch a spacecraft to go out to the planet Mars (without stopping there), and then come back. If the spacecraft never uses rockets after it leaves Earth, how long will it take the satellite to make its orbit?

1. The spacecraft will make one complete orbit in a year.
2. The spacecraft will take less than one year to make a complete orbit.
3. The spacecraft will take more than one year to make a complete orbit.

How long will it take the spacecraft to make a complete orbit around the Sun compared to the time it takes Mars to complete an orbit?

1. The spacecraft will make one complete orbit in the same amount of time it takes Mars to make a complete orbit.
2. The spacecraft will take less time to make a complete orbit than it takes Mars.
3. The spacecraft will take more time to make a complete orbit than it takes Mars.

A newly discovered asteroid is observed orbiting the Sun at an average distance of 4 astronomical units (AU). How long will it take to orbit the Sun?

1. 2.3 years
2. 4 years
3. 8 years
4. 16 years
5. 64 years

## Models of the Universe

The figure below shows a portion of Ptolemy's model of the universe. What phases would you see for Venus when it is at the positions given by letters if you are using a telescope on Earth?

The figure below shows a portion of Copernicus' model of the universe. If Venus was in the positions given by letters, what phases would you see through a telescope from Earth?

## Motion and Newton's Laws

You throw a ball straight up in the air. At the highest point, the ball's

1. velocity and acceleration are zero.
2. velocity is not zero but its acceleration is zero.
3. acceleration is not zero, but its velocity is zero.
4. velocity and acceleration are both not zero.

A car is sitting still on a road. The car's

1. velocity and acceleration are zero.
2. velocity is not zero but its acceleration is zero.
3. acceleration is not zero, but its velocity is zero.
4. velocity and acceleration are both not zero.

A car is travelling along a straight, flat road at constant speed. The car's

1. velocity and acceleration are zero.
2. velocity is not zero but its acceleration is zero.
3. acceleration is not zero, but its velocity is zero.
4. velocity and acceleration are both not zero.

A car is travelling at constant speed around a curve. The car's

1. velocity and acceleration are zero.
2. velocity is not zero but its acceleration is zero.
3. acceleration is not zero, but its velocity is zero.
4. velocity and acceleration are both not zero.

A crash test dummy is riding on a motorcycle but not wearing a seatbelt. The cycle hits a wall and stops. What is the best description of what happens to the dummy?

1. The dummy pops up in the air at the instant the cycle hits the wall.
2. The dummy keeps moving forward until it hits the wall.
3. The dummy stops at the same instant the cycle does.

Is there a net (unbalanced) force acting in the following situations?

1. A car is coming to a stop
2. A bus is speeding up.
3. An elevator moves upward at constant speed.
4. A bicycle goes around a curve.
5. A moon orbits Jupiter.

The pictures below show boxes (that are initially at rest) and the forces that are acting on them. In each case, what is going to happen to the box?

1. The box will move to the left.
2. The box will move to the right.
3. The box will move upward.
4. The box will move downward.
5. The box will not move.

Which of the following diagrams best represents the forces acting on a ball hanging from a string?

Which of the following diagrams best represents the forces acting on a cart sitting still on a table?

You are late for class and driving too fast when you enter into a sharp right turn. The tires lose their grip on the road. What is probably going to end up happening?

1. The car will skid to the right of the direction it was going at the time of the skid.
2. The car will skid in a straight line in the direction that it was going at the time of the skid.
3. The car will skid to the left of the direction it was going at the time of the skid.

A ball is rolling in a straight line as shown in the figure below (from the view of someone standing over the table). If it is struck on the left side, what is going to happen to its motion?

1. It will speed up, but will continue moving in the same direction.
2. It will slow down, but will continue moving in the same direction.
3. It will immediately start moving directly to the right.
4. It will immediately start moving directly to the left.
5. It will move in a straight line, but somewhat to the right of its original direction.
6. It will move in a straight line, but somewhat to the left of its original direction.
7. It will continue moving in the same direction at the same speed.

I am swinging a ball on a string counterclockwise around my head (as seen from above in the picture below). At the instant shown, In which direction is the ball's velocity pointing?

1. Toward me.
2. Away from me.
3. To the left.
4. To the right.

At the same instant, in which direction is there a net force acting?

1. Toward me.
2. Away from me.
3. To the left.
4. To the right.

I swing a ball on a string counterclockwise above my head (as seen from above in the picture below). At the point shown, I suddenly release the string. Which of the paths below would the ball most closely follow when released?

I roll a marble around a circular track that has a section cut out. When the marble reaches the end of the track, what path will it take?

The space shuttle fires its engine. What forces act on the space shuttle?

1. Two forces: one from the exhaust gas, and the equal and opposite force.
2. One force from the exhaust gas.
3. There is no force acting because they cancel out.

A red cart is going to hit a pair of blue carts with a spring-loaded pusher. (The pair of blue carts has twice the mass of the red cart.) After the hit, which cart will have accelerated (sped up) more?

1. The red cart.
2. The pair of blue carts.
3. Both experience the same acceleration.

Suppose you are an astronaut taking a space walk to fix your spacecraft with a hammer. Your tether line breaks and the jets on your backpack are out of fuel. How could you return to your spacecraft without the help of someone else?

1. throw the hammer at the ship
2. throw the hammer away from the ship
3. flap your arms
4. kiss your ship good-bye

An asteroid is moving through space at constant velocity. At the time shown, a rocket that is attached to the asteroid starts to fire continuously toward the bottom of the screen. Which of the paths would the asteroid most closely follow as the rocket fires?

A compact car and a large truck collide head-on and stick together. Which vehicle exerts the largest force during the collision?

1. The car.
2. The truck.
3. Both exert the same force.
4. Neither exerts a force on the other - the car gets smashed simply because it gets in the way of the truck.

A compact car and a large truck collide head-on and stick together. Which vehicle undergoes the largest acceleration during the collision?

1. The car.
2. The truck.
3. Both experience the same acceleration.
4. You can't tell without knowing how fast the vehicles were moving before the collision.

If the planet is moving with the velocity shown in blue, what will the Sun's gravitational force (red) be doing to the planet at the point shown?

1. Speeding it up
2. Slowing it down
3. Keeping same speed
1. Turning it to your left
2. Turning it to your right
3. Keeping same direction

## Gravity

A hypothetical planet system has planets in equally-spaced circular orbits. The planet masses are given in terms of the mass of the innermost planet. Which of the planets exerts the greatest gravitational force on the star?

You and your friend measure the strength of the force of gravity acting on both of you when you are on the surface of Earth. Your friend has 3 times as much mass as you do. The force on your friend is

1. 1/3 as large
2. 1/9 as large
3. 3 times as large
4. 9 times as large
5. the same
as the force on you.

An astronaut measures the strength of the force of gravity acting on him when he is on the surface of Earth and when he is 10 times farther away from the center of Earth. How do they compare?

1. When he is farther away, the force is 1/10th as large.
2. When he is farther away, the force is 1/100th as large
3. When he is farther away, the force is 1/1000th as large.
4. When he is farther away, the force is 10 times larger.
5. When he is farther away, the force is 100 times larger.
6. When he is farther away, the force is 1000 times larger.

A person measures the strength of the force of gravity acting on him when he is on the surface of Earth, and compares it to the force acting on his friend (who is twice as massive) when his friend is 10 times farther away from the center of Earth. How do they compare?

1. The force on his friend is 1/5th as large.
2. The force on his friend is 1/10th as large
3. The force on his friend is 1/25th as large.
4. The force on his friend is 1/50th as large.
5. The force on his friend is 1/100th as large.

An astronaut goes on the first mission to Mars. Mars has a mass that is only about one-tenth the mass of the Earth, and it is about half the size of Earth (so that she is closer to the center of the planet when she is standing on the surface). How will her weight on Mars compare to her weight on Earth?

1. Same as her weight on Earth.
2. 1/2 (50%) of her weight on Earth
3. 2/5 (40%) of her weight on Earth
4. 1/4 (25%) of her weight on Earth
5. 1/5 (20%) of her weight on Earth
6. 1/10 (10%) of her weight on Earth

Consider a person standing in an elevator that is accelerating upward. The upward force exerted by the elevator floor on the person is

1. larger than
2. identical to
3. smaller than

the downward weight of the person.

A bowling ball and a ball of paper are let go outside the airlock of a spaceship. The spaceship is orbiting Earth with its rockets off. After 10 minutes,

1. both objects will still be alongside the spaceship.
2. the bowling ball will be alongside the spaceship, but the paper ball would have been far behind.
3. both objects are far behind the spaceship.
4. the bowling ball will be falling to Earth, but the paper ball will be alongside the spaceship.
5. both objects would be falling to Earth.
6. 1/10 (10%) of her weight on Earth

If we fire a cannonball from a tall mountain as part of Newton's experiment (with no air resistance) and it lands almost half way around the world (as in the animation here using 6 km/s), what will happen if we fire the next cannonball a little faster?

1. The cannonball will go flying away from Earth.
2. The cannonball will orbit Earth.
3. The cannonball will go more than half way around Earth before crashing to the ground.

A spacecraft hovers near a small asteroid (with the help of its rocket) as they are both moving toward the right. Which of the paths would the asteroid most closely follow as time goes on?

If NASA sends a spacecraft to another planet (like Mercury) and wants to put it into orbit, what direction do the thrusters have to be pointed and fired?

1. In the direction the spacecraft is coming from
2. In the direction the spacecraft is going
3. Toward the planet
4. Away from the planet
5. The spacecraft doesn't need to use thrusters

## Light

A person's clothes appear dark blue when the fluorescent lights (white light) are on. How will the person's clothes appear when the street lamp (which emits pure yellow light) is on?

1. The clothes will appear blue.
2. The clothes will appear green.
3. The clothes will appear black.
4. The clothes will appear yellow.

A person's clothes appear dark red when the fluorescent lights (white light) are on. How will the person's clothes appear when the street lamp (which emits pure yellow light) is on?

1. The clothes will appear red.
2. The clothes will appear orange.
3. The clothes will appear black.
4. The clothes will appear yellow.

Suppose you put light through a prism, and all of the colors of the rainbow project to the front of class. If a red filter is put into the beam, what happens to the projected rainbow?

1. You see mostly red light; the blue and green disappear.
2. You see mostly blue light; the other colors disappear.
3. All of the colors turn red.

Which of the following models can explain what a red filter does to light?

1. Filters add color to light - red adds red, and so on.
2. Filters add a complementary color to light - red adds blue, for example.
3. Light is like little bullets, but there are different kinds of bullets. Filters stop some bullets, but not others.

If the light hitting the prism goes through a red filter first, what will you end up seeing on the screen?

1. The light that passes through the prism will be white.
2. The light that passes through the prism will be red.
3. The light that passes through the prism will be everything except red.
4. No light will pass through the prism.

What is a reasonable interpretation of the pictured experiment?

1. Prisms create new colors from white light.
2. Prisms add new colors to white light.
3. White light is a mixture of light with different colors.
4. Yellow light is a mixture of light with different colors.

Compared to other colors of visible light, red light has

1. higher energy and longer wavelength.
2. lower energy and longer wavelength.
3. lower energy and shorter wavelength.
4. higher energy and shorter wavelength.

Which of the following is true?

1. Radio photons have a longer wavelength than visible light photons.
2. X-ray photons have a larger frequency than visible light photons.
3. Infrared photons have a smaller energy than visible light photons.
4. All of the above.
5. None of the above.

Some of the questions above are taken from the following sources:

J. P. Adams, D. J. Loranz, E. E. Prather, and T. F. Slater. Lecture Tutorials for Introductory Astronomy -- Instructor's Guide, 2002 (Prentice Hall).

E. Mazur. Peer Instruction: A User's Manual, 1997 (Prentice Hall).

Last update: September 21, 2015