The solutions are here

14. The pressure inside a commercial airliner is maintained at 1.00 atm (105 Pa). What is the net outward force exerted on a 1.0 m ´ 2.0 m cabin door if the outside pressure is 0.30 atm?
a. 140 N
b. 1 400 N
c. 14 000 N
d. 140 000 N

17. The Greenland ice sheet can be one km thick. Estimate the pressure underneath the ice. (The density of ice is 918 kg/m³.)
a. 9.0 × 10⁵ Pa (9 atm)
b. 2.5 × 10⁶ Pa (25 atm)
c. 4.5 × 10⁶ Pa (45 atm)
d. 9.0 × 10⁶ Pa (90 atm)

18. What is the total mass of the Earth’s atmosphere? (The radius of the Earth is 6.4 × 10⁶ m, and atmospheric pressure at the surface is 10⁵ N/m².)
a. 5 × 10¹⁶ kg
b. 1 × 10¹⁸ kg
c. 5 × 10¹⁸ kg
d. 1 × 10²⁰ kg

23. A 15 000-N car on a hydraulic lift rests on a cylinder with a piston of radius 0.20 m. If a connecting cylinder with a piston of 0.040-m radius is driven by compressed air, what force must be applied to this smaller piston in order to lift the car?
a. 600 N
b. 1 500 N
c. 3 000 N
d. 15 000 N

23. A 15 000-N car on a hydraulic lift rests on a cylinder with a piston of radius 0.20 m. If a connecting cylinder with a piston of 0.040-m radius is driven by compressed air, what force must be applied to this smaller piston in order to lift the car?
a. 600 N
b. 1 500 N
c. 3 000 N
d. 15 000 N

29. How deep under the surface of a lake would the pressure be double that at the surface? (1 atm = 1.01 × 10⁵ Pa)
a. 1.00 m
b. 9.80 m
c. 10.3 m
d. 32.2 m

33. What volume of water is displaced by a submerged 2.0-kg cylinder made of solid aluminum? (aluminum density = 2.7 × 10³ kg/m³ and water density = 1.0 × 10³ kg/m³)
a. 7.4 × l0^-4 m³
b. 1.4 × 10³ m³
c. 9.9 × 10³ m³
d. 6.0 × 102 m³

36. The bottom of a flat-bottomed aluminum boat has an area of 4.0 m² and the boat’s mass is 60 kg. When set afloat in water, how far below the water surface is the boat bottom? (water density = 1.0 × 10³ kg/m3)
a. 0.060 m
b. 0.015 m
c. 0.030 m
d. 0.075 m

37. The bottom of a flat-bottomed aluminum boat has area = 4.0 m² and mass = 60 kg. If two fishermen and their fishing gear with total mass of 300 kg are placed in the boat, how much lower will the boat ride in the water? (H₂O density = 1.0 × 10³ kg/m³)
a. 0.15 m
b. 0.090 m
c. 0.075 m
d. 0.060 m

40. As ice floats in water, about 10% of the ice floats above the surface of the water. If we float some ice in a glass of water, what will happen to the water level as the ice melts?
a. The water level will rise 10% of the volume of the ice that melts.
b. The water level will rise, but not as much as the 10% indicated in answer A.
c. The water level will remain unchanged.
d. The water level will become lower.

41. A large stone is resting on the bottom of the swimming pool. The normal force of the bottom of the pool on the stone is equal to the:
a. weight of the stone.
b. weight of the water displaced.
c. sum of the weight of the stone and the weight of the displaced water.
d. difference between the weight of the stone and the weight of the displaced water.

43. A heavily loaded boat is floating in a pond. The boat sinks because of a leak. What happens to the surface level of the pond?
a. It stays the same.
b. It goes up.
c. It goes down.
d. More information is needed to reach a conclusion.
If you think the answer is d., maybe it will help to specxify that no air bubble is caught in the sinking boat.

44. A heavily loaded boat is floating in a pond. The boat starts to sink because of a leak but quick action plugging the leak stops the boat from going under although it is now deeper in the water. What happens to the surface level of the pond?
a. It stays the same.
b. It goes up.
c. It goes down.
d. More information is needed to reach a conclusion.

55. A hole is poked through the metal side of a drum holding water. The hole is 18 cm below the water surface. What is the initial speed of outflow?
a. 1.9 m/s
b. 2.96 m/s
c. 3.2 m/s
d. 3.5 m/s

56. Water comes down the spillway of a dam from an initial vertical height of 170 m. What is the highest possible speed of the water at the end of the spillway?
a. 15 m/s
b. 25 m/s
c. 58 m/s
d. 1 370 m/s

58. A fountain sends water to a height of 100 m. What must be the pressurization (above atmospheric) of the underground water system? (1 atm = 105 N/m2)
a. 1 atm
b. 4.2 atm
c. 7.2 atm
d. 9.8 atm

1. Which best describes the relationship between two systems in thermal equilibrium?
a. no net energy is exchanged
b. volumes are equal
c. masses are equal
d. zero velocity

5. What is the temperature of a system in thermal equilibrium with another system made up of ice and water at one atmosphere of pressure?
a. 0°F
b. 273 K
c. 0 K
d. 100°C

8. A substance is heated from 15°C to 35°C. What would the same incremental change be when registered in kelvins?
a. 20
b. 40
c. 36
d. 313

15. Which of the following properties can be used to measure temperature?
a. the color of a glowing object
b. the length of a solid
c. the volume of gas held at constant pressure
d. all of the above

17. A steel wire, 150 m long at 10°C, has a coefficient of linear expansion of 11 × 10^-6/C°. Give its change in length as the temperature changes from 10°C to 45°C.
a. 0.65 cm
b. 1.8 cm
c. 5.8 cm
d. 12 cm

19. What happens to a given mass of water as it is cooled from 4°C to zero?
a. expands
b. contracts
c. vaporizes
d. Neither expands, contracts, nor vaporizes.

22. A steel plate has a hole drilled through it. The plate is put into a furnace and heated. What happens to the size of the inside diameter of a hole as its temperature increases?
a. increases
b. decreases
c. remains constant
d. becomes elliptical

25. An automobile gas tank is filled to its capacity of 15.00 gallons with the gasoline at an initial temperature of 10°C. The automobile is parked in the sun causing the gasoline’s temperature to rise to 60°C. If the coefficient of volume expansion for gasoline is 9.6 ´ 10-4/C°, what volume runs out the overflow tube? Assume the change in volume of the tank is negligible.
a. 1.74 gallons
b. 1.18 gallons
c. 0.72 gallons
d. 0.30 gallons

27. What happens to a volume of water when its temperature is reduced from 8°C to 4°C?
a. density increases
b. density decreases
c. density remains constant
d. vaporizes

31. A long steel beam has a length of twenty-five meters on a cold day when the temperature is 0°C. What is the length of the beam on a hot day when T = 40°C? (α_steel= 1.1 × 10^-5/C°)
a. 25.000 44 m
b. 25.004 4 m
c. 25.011 m
d. 25.044 m

39. What happens to its moment of inertia when a steel disk is heated?
a. It increases.
b. It decreases.
c. It stays the same.
d. It increases for half the temperature increase and then decreases for the rest of the temperature increase.

41. An ideal gas is confined to a container with constant volume. The number of moles is constant. By what factor will the pressure change if the absolute temperature triples?
a. 1/9
b. 1/3
c. 3.0
d. 9.0

42. An ideal gas is confined to a container with adjustable volume. The number of moles and temperature are constant. By what factor will the volume change if pressure triples?
a. 1/9
b. 1/3
c. 3.0
d. 9.0

60. A spherical air bubble originating from a scuba diver at a depth of 18.0 m has a diameter of 1.0 cm. What will the bubble’s diameter be when it reaches the surface? (Assume constant temperature.)
a. 0.7 cm
b. 1.0 cm
c. 1.4 cm
d. 1.7 cm

67. Two ideal gases, X and Y, are thoroughly mixed and at thermal equilibrium in a single container. The molecular mass of X is 9 times that of Y. What is the ratio of root-mean-square velocities of the two gases, v_{X, rms} /v_{Y, rms}?
a. 9/1
b. 3/1
c. 1/3
d. 1/9

68. The absolute temperature of an ideal gas is directly proportional to which of the following properties, when taken as an average, of the molecules of that gas?
a. speed
b. momentum
c. mass
d. kinetic energy

70. If the temperature of an ideal gas contained in a box is increased:
a. the average velocity of the molecules in the box will be increased.
b. the average speed of the molecules in the box will be increased.
c. the distance between molecules in the box will be increased.
d. all of the above.

3. Heat flow occurs between two bodies in thermal contact when they differ in what property?
a. mass
b. specific heat
c. density
d. temperature

7. If heat is flowing from a table to a block of ice moving across the table, which of the following must be true?

a. The table is rough and there is friction between the table and ice.
b. The ice is cooler than the table.
c. The ice is changing phase.
d. All three are possible, but none is absolutely necessary.

9. Which of the following statements is true?
a. A hot object contains a lot of heat.
b. A cold object contains only a little heat.
c. Objects do not contain heat.
d. Statements a and b are true.

15. An inventor develops a stationary cycling device by which an individual, while pedaling, can convert all of the energy expended into heat for warming water. What minimum power must be generated if 300 g water (enough for 1 cup of coffee) is to be heated in 10 min from 20°C to 95°C? (1 cal = 4.186 J, the specific heat of water is 4 186 J/kg×°C)
a. 9 400 W
b. 590 W
c. 160 W
d. 31 W

17. A swimming pool heater has to be able to raise the temperature of the 40 000 gallons of water in the pool by 10.0 C°. How many kilowatt-hours of energy are required? (One gallon of water has a mass of approximately 3.8 kg and the specific heat of water is 4 186 J/kg×°C.)
a. 1 960 kWh
b. 1 770 kWh
c. 330 kWh
d. 216 kWh

20. A waterfall is 145 m high. What is the increase in water temperature at the bottom of the falls if all the initial potential energy goes into heating the water? (g = 9.8 m/s², cw = 4 186 J/kg×°C)
a. 0.16°C
b. 0.34°C
c. 0.69°C
d. 1.04°C

21. What is the temperature increase of 4.0 kg of water when heated by an 800-W immersion heater for 10 min? (c^w = 4 186 J/kg×°C)
a. 56°C
b. 51°C
c. 29°C
d. 14°C

26. A 2.00-kg copper rod is 50.00 cm long at 23°C. If 40 000 J are transferred to the rod by heat, what is its change in length? c_copper = 387 J/kg·°C and α_copper = 17 × 10-6/°C.
a. 0.022 cm
b. 0.044 cm
c. 0.059 cm
d. More information is needed.

28. A slice of bread contains about 100 kcal. If specific heat of a person were 1.00 kcal/kg·°C, by how many °C would the temperature of a 70.0?kg person increase if all the energy in the bread were converted to heat?
a. 2.25°C
b. 1.86°C
c. 1.43°C
d. 1.00°C

32. Find the final equilibrium temperature when 10.0 g of milk at 10.0°C is added to 160 g of coffee at 90.0°C. (Assume the specific heats of coffee and milk are the same as water and neglect the heat capacity of the container.)
a. 85.3°C
b. 77.7°C
c. 71.4°C
d. 66.7°C

34. Which of the following best describes a substance in which the temperature remains constant while at the same time it is experiencing an inward heat flow?
a. gas
b. liquid
c. solid
d. substance undergoing a change of state

37. Iced tea is made by adding ice to 1.8 kg of hot tea, initially at 80°C. How many kg of ice, initially at 0°C, are required to bring the mixture to 10°C? (L_f = 3.33 x 105 J/kg, c_w = 4 186 J/kg×°C)
a. 1.8 kg
b. 1.6 kg
c. 1.4 kg
d. 1.2 kg

39. 125 g of dry ice (solid CO₂) is dropped into a beaker containing 500 g of 66°C water. The dry ice converts directly to gas, leaving the solution. When the dry ice is gone, the final temperature of the water is 29°C. What is the heat of vaporization of solid CO₂? (c_water = 1.00 cal/g×°C)
a. 37 cal/g
b. 74 cal/g
c. 111 cal/g
d. 148 cal/g

40. In cloud formation, water vapor turns into water droplets which get bigger and bigger until it rains. This will cause the temperature of the air in the clouds to:
a. get warmer.
b. get cooler.
c. will not affect the temperature of the air in the clouds.
d. There is no air in clouds.

42. How much heat energy is required to vaporize a 1.0?g ice cube at 0°C? The heat of fusion of ice is 80 cal/g. The heat of vaporization of water is 540 cal/g, and cwater = 1.00 cal/g×°C.
a. 620 cal
b. 720 cal
c. 820 cal
d. 1 kcal

7. A system is acted on by its surroundings in such a way that it receives 50 J of heat while simultaneously doing 20 J of work. What is its net change in internal energy?
a. 70 J
b. 30 J
c. zero
d. -30 J

8. In an isothermal process for an ideal gas system (where the internal energy doesn’t change), which of the following choices best corresponds to the value of the work done on the system?
a. its heat intake
b. twice its heat intake
c. the negative of its heat intake
d. twice the negative of its heat intake

19. A 5-mol ideal gas system undergoes an adiabatic free expansion (a rapid expansion into a vacuum), going from an initial volume of 10 L to a final volume of 20 L. How much work is done on the system during this adiabatic free expansion?
a. -50 J
b. -10 J
c. zero
d. +50 J

20. Which of the following increases the internal energy of a solid metal rod?
a. raising it to a greater height
b. throwing it through the air
c. having the rod conduct heat
d. having the rod absorb heat

22. Heat is applied to an ice-water mixture to melt some of the ice. In this process:
a. work is done by the ice-water mixture.
b. the temperature increases.
c. the internal energy increases.
d. all of the above are correct.

28. A heat engine exhausts 3 000 J of heat while performing 1 500 J of useful work. What is the efficiency of the engine?
a. 15%
b. 33%
c. 50%
d. 60%

29. A heat engine operating between a pair of hot and cold reservoirs with respective temperatures of 500 K and 200 K will have what maximum efficiency?
a. 60%
b. 50%
c. 40%
d. 30%

31. According to the second law of thermodynamics, which of the following applies to the heat received from a high temperature reservoir by a heat engine operating in a complete cycle?
a. must be completely converted to work
b. equals the entropy increase
c. converted completely into internal energy
d. cannot be completely converted to work

32. The maximum theoretical thermodynamic efficiency of a heat engine operating between hot and cold reservoirs is a function of which of the following?
a. hot reservoir temperature only
b. cold reservoir temperature only
c. both hot and cold reservoir temperatures
d. None of the above choices are valid.

33. A heat engine receives 6 000 J of heat from its combustion process and loses 4 000 J through the exhaust and friction. What is its efficiency?
a. 33%
b. 40%
c. 67%
d. 73%

34. If a heat engine has an efficiency of 30% and its power output is 600 W, what is the rate of heat input from the combustion phase?
a. 1 800 W
b. 2 400 W
c. 2 000 W
d. 3 000 W

36. An electrical generating plant operates at a boiler temperature of 220°C and exhausts the unused heat into a nearby river at 18°C. What is the maximum theoretical efficiency of the plant? (0°C = 273 K)
a. 61%
b. 32%
c. 21%
d. 41%

39. In which system is heat usually transferred from the cooler part to the warmer part?
a. a stove as it heats up water
b. a refrigerator that is running
c. an electric fan that is running
d. none of the above, because it is impossible to transfer heat in this manner

50. A refrigerator has a coefficient of performance of 4.0. When removing 2.4 × 10⁴ J from inside the refrigerator, how much energy is sent into the environment?
a. 9.6 × 104 J
b. 3.0 × 104 J
c. 1.8 × 104 J
d. 0.60 × 104 J

56. A 2.00-kg block of ice is at STP (0°C, 1 atm) while it melts completely to water. What is its change in entropy? (For ice, L_f = 3.34 × 10⁵ J/kg)
a. zero
b. 584 J/K
c. 1 220 J/K
d. 2 450 J/K

57. One kilogram of water at 1.00 atm at the boiling point of 100°C is heated until all the water vaporizes. What is its change in entropy? (For water, L_v = 2.26 × 10⁶ J/kg)
a. 12 100 J/K
b. 6 060 J/K
c. 3 030 J/K
d. 1 220 J/K

61. The surface of the Sun is at approximately 5 700 K and the temperature of the Earth's surface is about 290 K. What total entropy change occurs when 1 000 J of heat energy is transferred from the Sun to the Earth?
a. 2.89 J/K
b. 3.27 J/K
c. 3.62 J/K
d. 3.97 J/K