1. no weight.
2. less weight than the roof.
3. the same amount of weight as the roof.
4. more weight than the roof.

How high will the smallest superball bounce when I drop the stack of four superballs from a foot above the ground?

1. It won't bounce - it will come to a dead stop.
2. It will bounce back to its starting point (1 foot).
3. It will bounce about 4 times as high (about 4 feet).
4. It will bounce about 8 times as high (about 8 feet).
5. It will bounce about 16 times as high (about 16 feet).
6. It will hit the ceiling.

Gas from a supernova explosion is expanding 0.1 light-years every decade, and the edges of the gas cloud are about 10 light-years from the center. How long has it been since the cloud started expanding?

1. 0.1 year
2. 1 year
3. 10 years
4. 100 years
5. 1000 years
6. 10,000 years

1. Tank A
2. Tank B
3. Tank C
4. More than one tank will empty at the same time.

You are going to start a barbecue marathon, but you have just one tank of propane for your gas grill. The tank contains 50 pounds of propane. To keep the grill at optimum cooking temperature, you have to burn 2.5 pounds of propane per hour. How long can your grilling marathon go on?

1. 2 hours
2. 2.5 hours
3. 20 hours
4. 25 hours
5. 50 hours
6. 125 hours

A small car has a 10 gallon gas tank, and it uses 1 gallon of gas every hour of driving. A large car has a 20 gallon tank and uses 2 gallons of gas every hour of driving. Which will run out of gas first?

1. The small car.
2. The large car.
3. They will both run out of gas at the same time.

A small car has a 10 gallon gas tank, and it uses 1 gallon of gas every hour of driving. A large car has a 20 gallon tank and uses 4 gallons of gas every hour of driving. Which will run out of gas first?

1. The small car.
2. The large car.
3. They will both run out of gas at the same time.

Consider the information given below about the lifetime of three main sequence stars A, B, and C.

Star A will be a main sequence star for 45,000 million years.

Star B will be a main sequence star for 70 million years.

Star C will be a main sequence star for 2 million years.

Which star has the greatest mass?

1. Star A
2. Star B
3. Star C
4. Stars A, B, and C all have approximately the same mass.

The bright star Vega has about 3 times the Sun's mass, and 60 times the Sun's luminosity. Vega will live

1. about 3 times longer than the Sun will.
2. about 20 times longer than the Sun will.
3. about 60 times longer than the Sun will.
4. about 180 times longer than the Sun will.
5. about 1/3rd as long as the Sun will.
6. about 1/20th as long as the Sun will.
7. about 1/60th as long as the Sun will.
8. about 1/180th as long as the Sun will.

Imagine you are camping, and are very afraid of the animal noises you hear coming from near camp. You want to build a campfire that will last all night and scare the animals off. In which of the following cases would your campfire last the shortest time?

1. Large number of logs, large logs, bright campfire
2. Large number of logs, small logs, bright campfire
3. Small number of logs, large logs, bright campfire
4. Large number of logs, large logs, faint campfire
5. Small number of logs, small logs, bright campfire
6. Small number of logs, large logs, faint campfire
7. Large number of logs, small logs, faint campfire

If the Sun doesn't have a source of heat inside, what does this say about the past history of the solar system?

1. The Sun must have been much hotter and brighter in the past, and the planets must have been much warmer.
2. The Sun and the solar system must have been about the same as they are today.
3. The Sun must have been much cooler and fainter in the past, and the planets must have been much cooler.

The HR Diagram below shows the 30 nearest stars. What are most nearby stars like (compared to the Sun - the yellow dot)?

1. hotter, less luminous
2. cooler, less luminous
3. hotter, more luminous
4. cooler, more luminous

1. Your thumb seems to move less when you switch between eyes.
2. Your thumb seems to move the same amount when you switch.
3. Your thumb seems to move more when you switch between eyes.
4. Your thumb doesn't seem to move when you switch.

Imagine that you are looking at the stars from Earth in January. The picture in the frame shows a view of the distant stars as seen from Earth. Which number would star A appear above as seen by someone on Earth in January?

Answer: 3. Hint: Draw a line between Earth and star A and continue it until it reaches the "Distant Stars". That shows where star A will appear to be. (Anything on that line will appear to be either directly in front of or directly behind star A.)

Which of the stars in the picture is closest to us?

Answer: F. Hint: Only two stars move during the year (A and F). Compare the pictures in the upper left and lower right to see the biggest shifts.

Two stars are photographed at the same time (the ones labeled "A") and then six months later (the ones labeled "B"). Between those two times the positions of the two stars appear to change. Which of the two stars is probably closer to us?

1. Star 1.
2. Star 2.
3. Both stars are at the same distance from us.
4. This cannot tell us which of the stars is closer.

1. One bulb.
2. Two bulbs.
3. Three bulbs.
4. Four bulbs.
5. More than four bulbs.

You are studying at you desk under an unshaded lamp with a 100 watt light bulb. Your roommate moves the lamp so that it is twice as far away from you, but replaces it with a 200 watt bulb. How bright is your desk compared to earlier?

1. 1/4th as bright.
2. 1/2 as bright.
3. The same brightness as before.
4. 2 times as bright.
5. 4 times as bright.

I am sunbathing on a planet with two stars that have the same temperature. I am lying on my side and trying to tan both sides at once. Star A lights my back. Star B lights my front, and it is 3 times as luminous as star A but it is 3 times farther from the planet. What will happen?

1. My front tans more.
2. My back tans more.
3. I will get a nice even tan.

For each pair of hot plates shown, which one that will boil water more quickly? If there is no way to tell, state that.

Answers: a) Left. b) Right. c) Left. d) No way to tell. Hint: The amount of heat the hot plate puts out depends on its temperature and its size. This is very similar to the case for stars. For d), one hot plate is hot but small, and one is cooler but larger, so it is not possible to tell which will boil water faster without more information.

The stars Antares and Spica each have the same luminosity. Antares is cooler than Spica. Which star is larger?

1. Antares
2. Spica
3. They will be the same size.
4. You didn't give me enough information to decide.

The star Spica is much more luminous than Sirius B. Spica and Sirius B have the same temperature. Which star has the greater surface area?

1. Spica
2. Sirius B
3. They will be the same size.
4. You didn't give me enough information to decide.

The star Spica is both hotter and more luminous than the Sun. Which star is larger?

1. Spica
2. The Sun
3. They will be the same size.
4. You didn't give me enough information to decide.

1. A
2. B
3. C
4. D
5. E

In the same picture above, Betelgeuse (a star that will probably go supernova in the future) is about 430 light-years away. Which dot best represents where it is?

1. A
2. B
3. C
4. D
5. E

Roughly how big is the red dot in the picture at right?

1. 1,000 light-years
2. 10,000 light-years
3. 25,000 light-years
4. 100,000 light-years
5. 500,000 light-years

The picture of the Milky Way is about 1 meter across (when shown on the screen in class). The Andromeda Galaxy is about the same size as the Milky Way and 2,500,000 light years away. In a scale model, where would we have to place Andromeda?

1. Next to the screen.
2. Near the door to the classroom.
3. At the library.
4. On the opposite side of campus.
5. In downtown San Diego.

Imagine you are watching two identical cars drive into a sharp turn. The first car is driving faster than the second car. Which of the cars is more likely to skid out during the turn?

1. The first (faster) car.
2. The second (slower) car.

Imagine you are studying two stars orbiting at the same distance from the centers of two different galaxies. One star is orbiting faster than the other. What does this tell you?

1. There is a stronger gravitational force pulling on the slower star.
2. There is a stronger gravitational force pulling on the faster star.
3. The gravitational forces must be the same.

Answer: 2. Hint: "Moving away" produces a redshift, so only objects 1 and 2 are possible answers (the line patterns have become redder). Faster motion makes larger color shifts.

A policeman's radar gun is not always able to measure your speed accurately. In which of the situations below would the cop be able to measure your speed using only the radar gun?

Answer: 4. Hint: A radar gun uses the Doppler shift to measure speed, but it can only motions that make distance get larger or smaller! So you have to be moving almost directly towards or away from the cop for him to measure your speed accurately. In #2, the cop is moving in the same direction, so that the distance between you is not changing, and again there would be no Doppler shift!

Imagine you are trying to accurately measure the speed of a star moving around our galaxy using ONLY the Doppler shift of the lines in its spectrum. For which of the stars in the diagram below would you be able to do this?

Answer: 4. Hint: Star 4 is the only one that is moving directly toward or away from the Sun, but the Sun itself is not moving toward or away from the star.

1. There is a stronger gravitational force on the slower star.
2. There is a stronger gravitational force on the faster star.
3. The gravitational forces are the same.

Most of the light released by a galaxy comes from the most luminous stars. Which of the following kinds of stars have the largest luminosities?

1. Main sequence stars with low mass, and giants.
2. Main sequence stars with high mass, and giants.
3. Main sequence stars with high mass, and white dwarfs.
4. Main sequence stars with low mass, and white dwarfs.

The light from a galaxy you are studying has a strong blue tint. Which of the following types of stars is probably releasing most of the light you see?

1. low-mass main sequence stars
2. high-mass main sequence stars
3. giant stars
4. supergiant stars
5. white dwarfs

Which of the following types of stars are you likely to find in a galaxy ONLY if there are large amounts of gas and dust that can be used to form stars?

1. Main sequence stars with high mass.
2. Main sequence stars with low mass.
3. Giant stars.
4. White dwarfs.

1. ``Galaxy B is not moving.''
2. ``Galaxy B is moving toward me (in galaxy C).''
3. ``Galaxy B is moving away from me (in galaxy C).''

Imagine that you are located in galaxy A and observe that galaxies B and C are both moving away from you (with galaxy C moving faster). If you asked an alien in galaxy C to describe what it sees, how would it answer?

1. ``Galaxies A and B are moving away from me with equal speeds.''
2. ``Galaxy A is moving away from me faster than galaxy B.''
3. ``Galaxy B is moving away from me faster than galaxy A.''

The drawing below represents the same group of galaxies at two different points in time during the history of the universe.

How would an alien in galaxy A describe what it sees?

1. "Galaxies B and E are moving away from me with equal speeds."
2. "Galaxy B is moving away from me faster than galaxy E."
3. "Galaxy E is moving away from me faster than galaxy B."

Imagine you simultaneously receive transmissions from two people that live on planets orbiting two different stars. The two pictures show the people at their 21st birthday parties. Which of the following is most likely?

1. Both people are the same age but are at different distances from you.
2. The people are actually different ages, but are at the same distance from you.
3. The person that is closer to you is actually the older of the two people.
4. The person that is farther from you is actually the older of the two peopple.

Fifteen years ago, a galaxy was discovered that was found to be 8 billion light years away. If our universe is approximately 13.5 billion years old, when did the galaxy emit the light that we observe?

1. 15 years ago
2. 5.5 billion years ago
3. 8 billion years ago
4. 13.5 billion years ago

Imagine you were observing a distant star located in a galaxy 100 million light-years away. By analyzing the starlight, you are able to tell that the star appears to be 10 million years old. You are able to predict that the star will have a lifetime of 50 million years.

How long does it take light to travel to us from the star?

1. 10 million years.
2. 50 million years.
3. 100 million years.

How old does the star appear to be to us on Earth?

1. 10 million years old.
2. 40 million years old.
3. 50 million years old.
4. 100 million years old.

How long will it be before we receive light from the supernova at this star's death?

1. 10 million years from now.
2. 40 million years from now.
3. 50 million years from now.
4. 100 million years from now.

When will or when did the supernova occur?

1. 40 million years ago.
2. 60 million years ago.
3. 100 million years ago.
4. 40 million years from now.
5. 140 million years from now.

The cosmic microwave background is composed of photons with wavelengths longer than visible light and longer than infrared light. If this background is blackbody radiation, what does this imply about the temperature?

1. The temperature is hotter than the center of the Sun.
2. The temperature is hotter than the surface of the Sun, but cooler than the center of the Sun.
3. The temperature is hotter than body temperature, but cooler than the surface of the Sun.
4. The temperature is cooler than body temperature.

If the expansion of the Universe makes the wavelengths of all light stretch the longer they travel, what is that going to do to the apparent temperature of the light reaching us from early in the Universe's history?

1. The temperature is going to appear to be lower than it actually was.
2. The temperature is going to appear to be higher than it actually was.
3. The temperature is going to appear to be exactly what it was originally.

What was the order the universe was put together (from start to finish)?

1. atoms, helium nuclei, carbon nuclei, stars
2. helium nuclei, atoms, stars, carbon nuclei
3. helium nuclei, carbon nuclei, atoms, stars
4. atoms, stars, helium nuclei, carbon nuclei
5. stars, atoms, helium nuclei, carbon nuclei

Which of the universes graphed below was expanding ("stretching") fastest in the past?

1. Universe A.
2. Universe B.
3. Universe C.

Imagine you are a policeman using a radar gun in the proper way. You measure the speed of a car that is near you, and find that it is going the speed limit. If the car was decelerating, what would you have found if you had measured its speed a few seconds earlier?

1. The car would have been doing the speed limit.
2. The car would have been going faster than the speed limit.
3. The car would have been going slower than the speed limit.

For an accelerating universe, which of the following is true?

1. The universe was stretching more quickly in the past.
2. The universe was stretching more slowly in the past.
3. The universe was stretching at the same rate as it is now.

1. The Sun is roughly the same width as Earth.
2. The Sun is roughly 10 times wider than Earth.
3. The Sun is roughly 100 times wider than Earth.
4. The Sun is roughly 1000 times wider than Earth.
5. The Sun is roughly 10,000 times wider than Earth.

If the Sun is 100 times larger than Earth, roughly how big should a shrunken Earth be compared to the basketball-Sun?

1. A basketball
2. A soccer ball
3. A softball
4. A baseball
5. A ping pong ball
6. A pea
7. A grain of sand

If the Sun is the size of a basketball, Proxima Centauri is the size of a large superball, but where should the star be (if the scale is the same)?

1. downtown San Diego (5 miles)
2. Los Angeles (110 miles)
3. St. Louis (1500 miles)
4. London (5500 miles)
5. the Moon (240,000 miles)

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).