Question 1

The emissivity of an ideal reflector has which of the following values?

Accepted Answer

A) 0 
B) 1 
C) 100 
D) infinity 
A) 0 
B) 1 
C) 100 
D) infinity

Question 2

An object at 30.0°C has its temperature increased to 41.0°C.The power then radiated by this object increases by how many percent?

Accepted Answer

A) 10.0 
B) 15.3 
C) 3.63 
D) 36.7 
E) 96.5 
A) 10.0 
B) 15.3 
C) 3.63 
D) 36.7 
E) 96.5

Question 3

When heating 2 kg of ice from -40°C,2 kg of water from 20°C to 50°C,and 2 kg of steam from 100°C to 125°C,which requires the most energy?

Accepted Answer

A) the ice 
B) the water 
C) The steam,it's obvious since it is the hottest. 
D) All three take the same amount. 
A) the ice 
B) the water 
C) The steam,it's obvious since it is the hottest. 
D) All three take the same amount.

Question 4

How much heat energy is required to vaporize a 4.40-g ice cube at 0°C? The heat of fusion of ice is 80.0 cal/g.The heat of vaporization of water is 540 cal/g,and cwater = 1.00 cal/g⋅°C.

Accepted Answer

A) 2 730 cal 
B) 3 170 cal 
C) 2 820 cal 
D) 3 520 cal 
E) 2 380 cal 
A) 2 730 cal 
B) 3 170 cal 
C) 2 820 cal 
D) 3 520 cal 
E) 2 380 cal

Question 5

Inside a house,stepping on a tile floor barefooted may feel almost cold,but stepping on carpet in an adjacent room feels comfortably warm.Why is this?

Accepted Answer

A) It's because the tile is below room temperature while the carpet is at room temperature. 
B) It's because the tile is at room temperature while carpet is normally warmer. 
C) It's because the thermal conductivity of tile is less than that of carpet. 
D) It's because the thermal conductivity of carpet is less than that of tile. 
A) It's because the tile is below room temperature while the carpet is at room temperature. 
B) It's because the tile is at room temperature while carpet is normally warmer. 
C) It's because the thermal conductivity of tile is less than that of carpet. 
D) It's because the thermal conductivity of carpet is less than that of tile.

Question 6

125 g of dry ice (solid CO2)is dropped into a beaker containing 600 g of 64.0°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 33.2°C.What is the heat of vaporization of solid CO2? (cwater = 1.00 cal/g⋅°C)

Accepted Answer

A) 160 cal/g 
B) 142 cal/g 
C) 118 cal/g 
D) 148 cal/g 
E) 154 cal/g 
A) 160 cal/g 
B) 142 cal/g 
C) 118 cal/g 
D) 148 cal/g 
E) 154 cal/g

Question 7

A piece of copper of mass 110 g is being drilled through with a 1/2" electric drill.The drill operates at 25.0 W and takes 25.0 s to bore through the copper.If all the energy from the drill heats the copper,find the copper's increase in temperature.ccopper = 387 J/kg⋅°C.

Accepted Answer

A) 18.4 C° 
B) 23.5 C° 
C) 14.7 C° 
D) 22.0 C° 
E) 29.4 C° 
A) 18.4 C° 
B) 23.5 C° 
C) 14.7 C° 
D) 22.0 C° 
E) 29.4 C°

Question 8

In winter,light-colored clothes will keep you warmer than dark-colored clothes if

Accepted Answer

A) you are warmer than your surroundings. 
B) you are at the same temperature as your surroundings. 
C) you are cooler than your surroundings. 
D) you are standing in sunlight. 
A) you are warmer than your surroundings. 
B) you are at the same temperature as your surroundings. 
C) you are cooler than your surroundings. 
D) you are standing in sunlight.

Question 9

Suppose working outside on a hot day someone generate 450 J of heat each second.If this energy is compensated for by the evaporation of sweat,how much water would be lost in an hour? The latent heat of fusion for water is 334 kJ/kg and for vaporization is 2 200 kJ/kg.

Accepted Answer

A) 4.9 liter 
B) 0.74 liter 
C) 0.50 liter 
D) 1.5 liter 
A) 4.9 liter 
B) 0.74 liter 
C) 0.50 liter 
D) 1.5 liter

Question 10

A blacksmith drops a 550 S1U1P1$\circ$S1S1P0F piece of iron into a vat of 75 S1U1P1$\circ$S1S1P0F water in order to cool it to 100 S1U1P1$\circ$S1S1P0F.How many kilograms of water are needed per kilogram of iron? Assume all the thermal energy from the iron is transferred to the water and none of the water evaporates.The specific heats of water and iron are 4186 J/kgS1U1P1$\circ$S1S1P0C and 448 J/kgS1U1P1$\circ$S1S1P0C,respectively.

Accepted Answer

A) 9.3 kg 
B) 0.78 kg 
C) 0.52 kg 
D) 1.9 kg 
A) 9.3 kg 
B) 0.78 kg 
C) 0.52 kg 
D) 1.9 kg

Question 11

Twenty grams of a solid at 70°C is place in 100 grams of a fluid at 20°C.Thermal equilibrium is reached at 30°C.The specific heat of the solid

Accepted Answer

A) is equal to that of the fluid. 
B) is less than that of the fluid. 
C) is more than that of the fluid. 
D) cannot be compared to that of a material in a different phase. 
A) is equal to that of the fluid. 
B) is less than that of the fluid. 
C) is more than that of the fluid. 
D) cannot be compared to that of a material in a different phase.

Question 12

A plot of the temperature versus the energy per kg added to a piece of ice as it goes from below freezing at −10°C to becoming steam at 110°C consists of straight lines,some horizontal and some with an upward slope.What do the upward slopes represent?

Accepted Answer

A) specific heats 
B) reciprocals of specific heats 
C) latent heats 
D) reciprocals of latent heats 
A) specific heats 
B) reciprocals of specific heats 
C) latent heats 
D) reciprocals of latent heats

Question 13

How much heat energy must be removed from 250 g of oxygen at 21.0°C to liquefy it at −183°C? (The specific heat of oxygen gas is 0.218 cal/g⋅°C,and its heat of vaporization is 50.9 cal/g. )

Accepted Answer

A) 4.8E+4 cal 
B) 2.4E+4 cal 
C) 6.0E+3 cal 
D) 1.2E+4 cal 
E) 3.6E+4 cal 
A) 4.8E+4 cal 
B) 2.4E+4 cal 
C) 6.0E+3 cal 
D) 1.2E+4 cal 
E) 3.6E+4 cal

Question 14

Which of the following involves the greatest heat transfer?

Accepted Answer

A) One gram of steam at 100°C changing to water at 100°C. 
B) One gram of ice at 0°C changing to water at 0°C. 
C) One gram of water cooling from 100°C to 0°C. 
D) One gram of ice heating from −100°C to 0°C. 
A) One gram of steam at 100°C changing to water at 100°C. 
B) One gram of ice at 0°C changing to water at 0°C. 
C) One gram of water cooling from 100°C to 0°C. 
D) One gram of ice heating from −100°C to 0°C.

Question 15

Marc attaches a falling 328-kg object with a rope through a pulley to a paddle wheel shaft.He places the system in a well-insulated tank holding 23.2 kg of water.When the object falls,it causes the paddle wheel to rotate and churn the water.If the object falls a vertical distance of 88.6 m at constant speed,what is the temperature change of the water? (1 kcal = 4 186 J,the specific heat of water is 4 186 J/kg⋅°C,and g = 9.80 m/s2)

Accepted Answer

A) 17 000 C° 
B) 2 930 C° 
C) 2.93 C° 
D) 0.587 C° 
E) 5.87 C° 
A) 17 000 C° 
B) 2 930 C° 
C) 2.93 C° 
D) 0.587 C° 
E) 5.87 C°

Question 16

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?

Accepted Answer

A) gas 
B) liquid 
C) solid 
D) substance undergoing a change of state 
A) gas 
B) liquid 
C) solid 
D) substance undergoing a change of state

Question 17

Which of the following produces greenhouse gases?

Accepted Answer

A) burning fossil fuel 
B) digestive processes in cows 
C) automobile pollution 
D) all of the above 
A) burning fossil fuel 
B) digestive processes in cows 
C) automobile pollution 
D) all of the above

Question 18

Which one of the following processes of heat transfer requires the presence of a fluid?

Accepted Answer

A) conduction 
B) radiation 
C) convection 
D) none of the above choices are valid 
A) conduction 
B) radiation 
C) convection 
D) none of the above choices are valid

Question 19

In a greenhouse,electromagnetic energy in the form of visible light enters the glass panes and is absorbed and then reradiated.What happens to this reradiated electromagnetic radiation from within the greenhouse?

Accepted Answer

A) 100% returns to the atmosphere. 
B) It's partially blocked by glass. 
C) It's transformed into ultraviolet upon striking the glass. 
D) It's reflected as visible light upon striking the glass. 
A) 100% returns to the atmosphere. 
B) It's partially blocked by glass. 
C) It's transformed into ultraviolet upon striking the glass. 
D) It's reflected as visible light upon striking the glass.

Question 20

Arrange from smallest to largest: the BTU,the joule,and the calorie.

Accepted Answer

A) BTU,J,cal 
B) J,cal,BTU 
C) cal,BTU,J 
D) J,BTU,cal 
A) BTU,J,cal 
B) J,cal,BTU 
C) cal,BTU,J 
D) J,BTU,cal

Exam 11: Energy in Thermal Processes

The emissivity of an ideal reflector has which of the following values?

An object at 30.0°C has its temperature increased to 41.0°C.The power then radiated by this object increases by how many percent?

When heating 2 kg of ice from -40°C,2 kg of water from 20°C to 50°C,and 2 kg of steam from 100°C to 125°C,which requires the most energy?

How much heat energy is required to vaporize a 4.40-g ice cube at 0°C? The heat of fusion of ice is 80.0 cal/g.The heat of vaporization of water is 540 cal/g,and cwater = 1.00 cal/g⋅°C.

Inside a house,stepping on a tile floor barefooted may feel almost cold,but stepping on carpet in an adjacent room feels comfortably warm.Why is this?

125 g of dry ice (solid CO2)is dropped into a beaker containing 600 g of 64.0°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 33.2°C.What is the heat of vaporization of solid CO2? (cwater = 1.00 cal/g⋅°C)

A piece of copper of mass 110 g is being drilled through with a 1/2" electric drill.The drill operates at 25.0 W and takes 25.0 s to bore through the copper.If all the energy from the drill heats the copper,find the copper's increase in temperature.ccopper = 387 J/kg⋅°C.

In winter,light-colored clothes will keep you warmer than dark-colored clothes if

Suppose working outside on a hot day someone generate 450 J of heat each second.If this energy is compensated for by the evaporation of sweat,how much water would be lost in an hour? The latent heat of fusion for water is 334 kJ/kg and for vaporization is 2 200 kJ/kg.

Twenty grams of a solid at 70°C is place in 100 grams of a fluid at 20°C.Thermal equilibrium is reached at 30°C.The specific heat of the solid

A plot of the temperature versus the energy per kg added to a piece of ice as it goes from below freezing at −10°C to becoming steam at 110°C consists of straight lines,some horizontal and some with an upward slope.What do the upward slopes represent?

How much heat energy must be removed from 250 g of oxygen at 21.0°C to liquefy it at −183°C? (The specific heat of oxygen gas is 0.218 cal/g⋅°C,and its heat of vaporization is 50.9 cal/g. )

Which of the following involves the greatest heat transfer?

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?

Which of the following produces greenhouse gases?

Which one of the following processes of heat transfer requires the presence of a fluid?

In a greenhouse,electromagnetic energy in the form of visible light enters the glass panes and is absorbed and then reradiated.What happens to this reradiated electromagnetic radiation from within the greenhouse?

Arrange from smallest to largest: the BTU,the joule,and the calorie.

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How much heat energy is required to vaporize a 4.40-g ice cube at 0°C? The heat of fusion of ice is 80.0 cal/g.The heat of vaporization of water is 540 cal/g,and c_water = 1.00 cal/g⋅°C.

125 g of dry ice (solid CO₂)is dropped into a beaker containing 600 g of 64.0°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 33.2°C.What is the heat of vaporization of solid CO₂? (c_water = 1.00 cal/g⋅°C)

A piece of copper of mass 110 g is being drilled through with a ¹/₂" electric drill.The drill operates at 25.0 W and takes 25.0 s to bore through the copper.If all the energy from the drill heats the copper,find the copper's increase in temperature.c_copper = 387 J/kg⋅°C.