Question 1

Fifty kJ of heat is added to a 10-kg piece of lead at its melting point of 330$\degree$C and 2 kg of lead melts. The heat of fusion of lead is

Accepted Answer

A)  2.5 kJ/kg. 
B)  3.3 kJ/kg. 
C)  5 kJ/kg. 
D)  25 kJ/kg.

Question 2

The entropy of a system is a measure of its

Accepted Answer

A)  temperature. 
B)  heat content. 
C)  density. 
D)  disorder.

Question 3

The heat a refrigerator absorbs from its contents is

Accepted Answer

A)  less than it gives off. 
B)  the same amount it gives off. 
C)  more than it gives off. 
D)  Any of these choices, depending on its design.

Question 4

A refrigerator

Accepted Answer

A)  produces cold. 
B)  changes heat to cold. 
C)  causes heat to disappear. 
D)  removes heat from a region and carries it elsewhere.

Question 5

The pressure at the bottom of a barrel filled with liquid does not depend on the

Accepted Answer

A)  acceleration of gravity. 
B)  liquid density. 
C)  height of the liquid. 
D)  area of the liquid surface.

Question 6

A container holds 1 g of air at atmospheric pressure. When an additional gram of air is pumped into the container and there is no change in temperature, the new pressure is

Accepted Answer

A)  0.5 atm. 
B)  1 atm. 
C)  2 atm. 
D)  4 atm.

Question 7

Steam at 100$\degree$C is more dangerous than the same mass of water at 100$\degree$C because the steam

Accepted Answer

A)  is less dense. 
B)  moves faster. 
C)  has a higher specific heat. 
D)  releases a great deal of heat when it condenses.

Question 8

The work output of every heat engine

Accepted Answer

A)  equals its heat intake. 
B)  equals the difference between its heat intake and heat exhaust. 
C)  depends only on its intake temperature. 
D)  depends only on its exhaust temperature.

Question 9

Molecular motion in a gas is the minimum possible at

Accepted Answer

A)  0$\degree$F. 
B)  0$\degree$C. 
C)  0 K. 
D)  -273 K.

Question 10

The freezing point of a substance is always lower than its

Accepted Answer

A)  melting point. 
B)  boiling point. 
C)  heat of fusion. 
D)  heat of vaporization.

Question 11

Which of the following is not true of molecular motion in a gas?

Accepted Answer

A)  There is no order in the motion. 
B)  There is no uniformity of speed or direction. 
C)  There is a definite average speed at a given temperature. 
D)  There is a definite average direction of motion at a given temperature.

Question 12

Radiation is emitted

Accepted Answer

A)  only by liquids. 
B)  only by solids. 
C)  only by liquids and solids. 
D)  by liquids, solids, and gases.

Question 13

When 90 kJ is removed from a 2-kg copper bar, its temperature drops from 200$\degree$C to 85$\degree$C. The specific heat of copper is

Accepted Answer

A)  0.16 kJ/kg$\degree$C. 
B)  0.19 kJ/kg$\degree$C. 
C)  0.23 kJ/kg$\degree$C. 
D)  0.39 kJ/kg$\degree$C.

Question 14

A 400-kg concrete block is 1 m long, 0.6 m wide, and 0.3 m high. It can exert three different pressures on a horizontal surface, depending on which face it rests on. The highest pressure is

Accepted Answer

A)  0.7 kPa. 
B)  2.2 kPa. 
C)  13.1 kPa. 
D)  21.8 kPa.

Question 15

When a liquid becomes a vapor,

Accepted Answer

A)  its temperature must decrease. 
B)  its temperature must increase. 
C)  it must absorb heat. 
D)  it must give off heat.

Question 16

A typical metabolic rate while walking is

Accepted Answer

A)  10 W. 
B)  50 W. 
C)  300 W. 
D)  1.2 kW.

Question 17

Which of the following quantities is independent of the size and shape of an object composed of a given material?

Accepted Answer

A)  volume 
B)  mass 
C)  weight 
D)  density

Question 18

Heat transfer in a vacuum

Accepted Answer

A)  can take place only by radiation. 
B)  can take place only by radiation and convection. 
C)  can take place by radiation, convection, and conduction. 
D)  cannot take place.

Question 19

The specific heat of water is 4.2 kJ/kg$\degree$C. How long will it take for a 2-kW heating element to raise the temperature of 30 kg of water from 20$\degree$C to 80$\degree$C?

Accepted Answer

A)  6.3 min 
B)  15 min 
C)  63 min 
D)  84 min

Question 20

The physics of a heat engine cannot be used to understand the operation of a

Accepted Answer

A)  nuclear reactor. 
B)  heat pump. 
C)  refrigerator. 
D)  diesel engine.

Exam 5: Matter and Heat

Fifty kJ of heat is added to a 10-kg piece of lead at its melting point of 330 $\degree$ C and 2 kg of lead melts. The heat of fusion of lead is

The entropy of a system is a measure of its

The heat a refrigerator absorbs from its contents is

A refrigerator

The pressure at the bottom of a barrel filled with liquid does not depend on the

A container holds 1 g of air at atmospheric pressure. When an additional gram of air is pumped into the container and there is no change in temperature, the new pressure is

Steam at 100 $\degree$ C is more dangerous than the same mass of water at 100 $\degree$ C because the steam

The work output of every heat engine

Molecular motion in a gas is the minimum possible at

The freezing point of a substance is always lower than its

Which of the following is not true of molecular motion in a gas?

Radiation is emitted

When 90 kJ is removed from a 2-kg copper bar, its temperature drops from 200 $\degree$ C to 85 $\degree$ C. The specific heat of copper is

A 400-kg concrete block is 1 m long, 0.6 m wide, and 0.3 m high. It can exert three different pressures on a horizontal surface, depending on which face it rests on. The highest pressure is

When a liquid becomes a vapor,

A typical metabolic rate while walking is

Which of the following quantities is independent of the size and shape of an object composed of a given material?

Heat transfer in a vacuum

The specific heat of water is 4.2 kJ/kg $\degree$ C. How long will it take for a 2-kW heating element to raise the temperature of 30 kg of water from 20 $\degree$ C to 80 $\degree$ C?

The physics of a heat engine cannot be used to understand the operation of a

Exam 5: Matter and Heat

Fifty kJ of heat is added to a 10-kg piece of lead at its melting point of 330 °\degree° C and 2 kg of lead melts. The heat of fusion of lead is

The entropy of a system is a measure of its

The heat a refrigerator absorbs from its contents is

A refrigerator

The pressure at the bottom of a barrel filled with liquid does not depend on the

A container holds 1 g of air at atmospheric pressure. When an additional gram of air is pumped into the container and there is no change in temperature, the new pressure is

Steam at 100 °\degree° C is more dangerous than the same mass of water at 100 °\degree° C because the steam

The work output of every heat engine

Molecular motion in a gas is the minimum possible at

The freezing point of a substance is always lower than its

Which of the following is not true of molecular motion in a gas?

Radiation is emitted

When 90 kJ is removed from a 2-kg copper bar, its temperature drops from 200 °\degree° C to 85 °\degree° C. The specific heat of copper is

A 400-kg concrete block is 1 m long, 0.6 m wide, and 0.3 m high. It can exert three different pressures on a horizontal surface, depending on which face it rests on. The highest pressure is

When a liquid becomes a vapor,

A typical metabolic rate while walking is

Which of the following quantities is independent of the size and shape of an object composed of a given material?

Heat transfer in a vacuum

The specific heat of water is 4.2 kJ/kg °\degree° C. How long will it take for a 2-kW heating element to raise the temperature of 30 kg of water from 20 °\degree° C to 80 °\degree° C?

The physics of a heat engine cannot be used to understand the operation of a

Fifty kJ of heat is added to a 10-kg piece of lead at its melting point of 330 $\degree$ C and 2 kg of lead melts. The heat of fusion of lead is

Steam at 100 $\degree$ C is more dangerous than the same mass of water at 100 $\degree$ C because the steam

When 90 kJ is removed from a 2-kg copper bar, its temperature drops from 200 $\degree$ C to 85 $\degree$ C. The specific heat of copper is

The specific heat of water is 4.2 kJ/kg $\degree$ C. How long will it take for a 2-kW heating element to raise the temperature of 30 kg of water from 20 $\degree$ C to 80 $\degree$ C?