1. When a boat sails from fresh water to salt water, the boat will float:
(a) Lower in the water.
(b) Higher in the water.
(c) At the same water level.
(d) None of these.
2. Pour a liter of water at 40 degrees C into a liter of water at 20 degress C and the final temperature of the two becomes
(a) Less than 30 degrees C.
(b) At or about 30 degrees C.
(c) More than 30 degrees C.
3. When a volume of air is compressed, its temperature
(a) Increases.
(b) Decreases.
(c) Neither increases not decreases.
4. Food in a pressure cooker is cooked faster because of the
(a) Higher temperature.
(b) Greater rate of bubble formation in the water.
(c) Increased internal energy in the water.
(d) All of these.
(e) None of these.
5. Two identical blocks of iron, one at 10 degrees C and the other at 20 degrees C, are put in contact. Suppose the cooler block cools to 5 degrees C and the warmer block warms to 25 degrees C. This would violate the
(a) 1st law of thermodynamics.
(b) 2nd law of thermodynamics.
(c) Both of these.
(d) Neither of these.
6. The ideal efficiency for a heat engine operating between the temperatures of 227 degrees C and 27 degrees C is:
(a) 20%.
(b) 25%.
(c) 40%.
(d) 88%.
7. The ideal efficiency for a heat engine operating between temperatures of 270K and 300 K is
(a) 10%.
(b) 24%.
(c) 80%.
(d) 89%.
(e) None of these.
8. According to special theory of relativity, all laws of nature are the same in reference frames that
(a) Accelerate.
(b) Move in circles.
(c) Move at constant velocity.
(d) Oscillate.
(e) None of these.
9. A woman standing on the ground sees a rocket ship move past her at 95% the speed of light. Compared to when the rocket is at rest, the woman measures the rocket’s length as:
(a) Longer.
(b) Shorter.
(c) Wider.
(d) Same size.
10. Consider a planet at rest and a spaceship that whizzes past the planet at high speed. An observer on the planet sees a contracted spaceship, while an observer on the spaceship sees
(a) A contracted planet.
(b) An expanded planet.
(c) A normal planet.
(d) Could be contracted or expanded depending on the direction of travel.
11. Compared to standard earth time, there is a physical slowing of your time when you travel at
(a) Relativistic speeds.
(b) Everyday low speeds.
(c) Both of these.
(d) None of these.
12. At the top of very tall skyscraper, a sensitive watch will run
(a) Slow.
(b) Fast.
(c) The same as at 1 g.
13. If the part of an iceberg that extends above the water were suddenly removed, the
(a) Iceberg would sink.
(b) Buoyant force on the iceberg would decrease.
(c) Density of the iceberg would change.
(d) Pressure on the bottom of the iceberg would increase.
(e) None of these.
14. If a weighted air-filled balloon (expandable) sinks in deep water, it will
(a) Likely sink to an equilibrium level before reaching bottom.
(b) Likely burst is water pressure is great enough.
(c) Become less dense as it sinks.
(d) Be acted on by continually decreasing buoyant force.
(e) None of these.
15. A refrigerator
(a) Produces cold.
(b) Causes heat to disappear.
(c) Removes heat from inside of refrigerator.
(d) Changes heat into cold.
(e) None of these.
16. According to relativity theory, if a space trip finds a son or daughter biologically older that his or her parents, then the space trip is taken by the
(a) Son or daughter.
(b) Parents.
(c) Either.
(d) Neither, it can’t be done.
17. From a general relativistic point of view, a person on the ground floor of a skyscraper ages
(a) Faster than a person on the top floor.
(b) Slower that a person on the top floor.
(c) At the same speed as a person on the top floor.
18. A cold piece of metal is dropped into insulated container of hot water. After the system has reached an equilibrium temperature, the
(a) Entropy of metal has decreased.
(b) Entropy of the water has increased.
(c) Net charge in entropy of the system is zero.
(d) Entropy of the system has increased.
19. As a baby grows into an adult, the entropy of the universe
(a) Increases.
(b) Stays the same.
(c) Decreases.
20. How much work per second (power) is required by a refrigerator that takes 800 J of thermal energy from a cold region each second and exhausts 1200 J each second to a hot region?
(a) 400 W
(b) 800 W
(c) 1200 W
(d) 2000 W