Question 1

Two kilograms of water at 100$\degree$C is converted to steam at 1 atm. Find the change in internal energy (in J). (Lv = 2.26 *106 J/kg.)

Accepted Answer

A) 2.1 * 104 
B) 4.5 *106 
C) 3.4 F* 105 
D) 4.2 * 106 
E) 2.1 *106 
A) 2.1 * 104 
B) 4.5 *106 
C) 3.4 F* 105 
D) 4.2 * 106 
E) 2.1 *106 D

Question 2

Determine the work done by 5 moles of an ideal gas that is kept at 100$\degree$C in an expansion from 1 litre to 5 litres.

Accepted Answer

A) 2.5 *104 J 
B) 1.1 * 104 J 
C) 6.7 * 103 J 
D) 2.9 *103 J 
E) 8.4 * 103 J 
A) 2.5 *104 J 
B) 1.1 * 104 J 
C) 6.7 * 103 J 
D) 2.9 *103 J 
E) 8.4 * 103 J A

Question 3

A team of people who travelled to the North Pole by dogsled lived on butter because they needed to consume 25 000 kilo-Joules each day. Because the ice there is lumpy and irregular, they had to help the dogs by pushing and lifting the load. Assume they had a 16-hour working day and that each person could lift a 500 N load. How many times would a person have to lift this weight 1.00 m upwards in a constant gravitational field where $g=9.80 \frac{\mathrm{~m}}{\mathrm{~s}^{2}}$ to do the work equivalent to 25 000 kJ?

Accepted Answer

A) 50.2 
B) 492 
C) 5130 
D) 50 200 
E) 492 000 
A) 50.2 
B) 492 
C) 5130 
D) 50 200 
E) 492 000 D

Question 4

In an isobaric process:

Accepted Answer

A) the volume remains constant. 
B) the temperature remains constant. 
C) the pressure remains constant. 
D) no heat is transferred between a system and its surroundings. 
E) the internal energy is constant. 
A) the volume remains constant. 
B) the temperature remains constant. 
C) the pressure remains constant. 
D) no heat is transferred between a system and its surroundings. 
E) the internal energy is constant.

Question 5

A 5-g coin is dropped from a 300-m building. If it reaches a terminal velocity of 45 m/s, and the rest of the energy is converted to heating the coin, what is the change in temperature (in $\degree$C) of the coin? (The specific heat of copper is 387 J/kg.$\degree$C.)

Accepted Answer

A) 9 
B) 2 
C) 5 
D) 21 
E) 0.5 
A) 9 
B) 2 
C) 5 
D) 21 
E) 0.5

Question 6

We are able to define a mechanical equivalent for heat because:

Accepted Answer

A) some thermal energy can be converted into mechanical energy. 
B) mechanical energy can be converted into thermal energy. 
C) work can be converted into thermal energy. 
D) some thermal energy can be converted into work. 
E) all of the above can occur. 
A) some thermal energy can be converted into mechanical energy. 
B) mechanical energy can be converted into thermal energy. 
C) work can be converted into thermal energy. 
D) some thermal energy can be converted into work. 
E) all of the above can occur.

Question 7

A child has a temperature of 101 $\degree$F. If her total cross-sectional area is 2 m2, find the energy lost each second (in W) due to radiation, assuming the emissivity is 1. (Assume the room temperature is 70 $\degree$F.)

Accepted Answer

A) 217 
B) 180 
C) 90 
D) 68 
E) 850 
A) 217 
B) 180 
C) 90 
D) 68 
E) 850

Question 8

A 100-kg student eats an 840-kJ doughnut. To 'burn it off', he decides to climb the steps of a tall building. How high (in m) would he have to climb to expend an equivalent amount of work?

Accepted Answer

A) 273 
B) 623 
C) 418 
D) 857 
E) 8400 
A) 273 
B) 623 
C) 418 
D) 857 
E) 8400

Question 9

The Earth intercepts 1.27 * 1017 W of radiant energy from the sun. Suppose the Earth, of volume 1.08 * 1021 m3, was composed of water. How long would it take for the Earth at 0$\degree$C to reach 100$\degree$C, if none of the energy was radiated or reflected back out into space?

Accepted Answer

A) 26.9 y 
B) 113 y 
C) 2.69 * 104 y 
D) 1.13*105 y 
E) 2.69 *107 y 
A) 26.9 y 
B) 113 y 
C) 2.69 * 104 y 
D) 1.13*105 y 
E) 2.69 *107 y

Question 10

A styrofoam container used as a Esky contains a block of ice at 0$\degree$C. If 225 grams of ice melts in 1 hour, how much heat energy per second is passing through the walls of the container? (The heat of fusion of ice is 3.33 * 105 J/kg).

Accepted Answer

The answer of A styrofoam container used as a Esky...

Question 11

Gas in a container increases its pressure from 1 atm to 3 atm while keeping its volume constant. Find the work done (in J) by the gas if the volume is 5 litres.

Accepted Answer

A) 0 
B) 3 
C) 5 
D) 15 
E) 15 *102 
A) 0 
B) 3 
C) 5 
D) 15 
E) 15 *102

Question 12

In a thermodynamic process, the internal energy of a system in a container with adiabatic walls decreases by 800 J. Which statement is correct?

Accepted Answer

A) The system lost 800 J by heat transfer to its surroundings. 
B) The system gained 800 J by heat transfer from its surroundings. 
C) The system performed 800 J of work on its surroundings. 
D) The surroundings performed 800 J of work on the system. 
E) The 800 J of work done by the system was equal to the 800 J of heat transferred to the system from its surroundings. 
A) The system lost 800 J by heat transfer to its surroundings. 
B) The system gained 800 J by heat transfer from its surroundings. 
C) The system performed 800 J of work on its surroundings. 
D) The surroundings performed 800 J of work on the system. 
E) The 800 J of work done by the system was equal to the 800 J of heat transferred to the system from its surroundings.

Question 13

Star A has a radius of 200 000 km and a surface temperature of 6000 K. Star B has a radius of 400 000 km and a surface temperature of 3000 K. The emissivity of both stars is the same. What is the ratio of the rate of energy radiated by Star A to that of Star B?

Accepted Answer

The answer of Star A has a radius of 200...

Question 14

Five moles of an ideal gas expands isothermally at 100$\degree$C to five times its initial volume. Find the heat flow into the system.

Accepted Answer

A) 2.5* 104 J 
B) 1.1 * 104 J 
C) 6.7 * 103 J 
D) 2.9 *103 J 
E) 7.0 * 102 J 
A) 2.5* 104 J 
B) 1.1 * 104 J 
C) 6.7 * 103 J 
D) 2.9 *103 J 
E) 7.0 * 102 J

Question 15

A gas expands from A to B as shown in the graph. Calculate the work (in joules) done by the gas. (1 atm= 1.01 *105 N/m2.)

Accepted Answer

A) 12 
B) 24 
C) 1.21 * 106 
D) 2.42 * 106 
E) 3.64 *106 
A) 12 
B) 24 
C) 1.21 * 106 
D) 2.42 * 106 
E) 3.64 *106

Question 16

A cup of coffee is enclosed on all sides in an insulated container 1/2 cm thick in the shape of a cube 10 cm on a side. The temperature of the coffee is 95$\degree$C, and the temperature of the surroundings is 21$\degree$C. Find the rate of heat loss (in J/s) due to conduction if the thermal conductivity of the cup is 2 *10-4 cal/s.cm.$\degree$C.

Accepted Answer

A) 62 
B) 74 
C) 230 
D) 160 
E) 12 
A) 62 
B) 74 
C) 230 
D) 160 
E) 12

Question 17

The R value of a particular brand of 'pink batt' roof insulation is 3 m2 K W-1. If the pink batts are 6cm thick, what is their thermal conductivity (in W m-1 K-1)?

Accepted Answer

A) 3 
B) 0.18 
C) 0.02 
D) 50 
E) 1 
A) 3 
B) 0.18 
C) 0.02 
D) 50 
E) 1

Question 18

Steel blocks A and B, which have equal masses, are at TA = 300 $\degree$C and TB = 400 $\degree$C. Block C, with mC = 2mA, is at TC = 350 $\degree$C. Blocks A and B are placed in contact, isolated, and allowed to come into equilibrium. Then they are placed in contact with block C. At that instant:

Accepted Answer

A) TA = TB  TC. 
D) TA + TB = TC. 
E) TA -TB = TC. 
A) TA = TB  TC. 
D) TA + TB = TC. 
E) TA -TB = TC.

Question 19

The R-value of an insulating material is the thickness of the material divided by its thermal conductivity. When an insulating material consists of three layers with R-values R1, R2 and R3, the overall R-value of the insulation is given by:

Accepted Answer

A) R = R1 + R2 + R3. 
B)  $R=\frac{R_{1} R_{2}+R_{1} R_{3}+R_{2} R_{3}}{R_{1}+R_{2}+R_{3}}$ . 
C)  $R=\frac{R_{1} R_{2} R_{3}}{R_{1} R_{2}+R_{1} R_{3}+R_{2} R_{3}}$ . 
D)  $\frac{1}{R}=\frac{1}{R_{1}+R_{2}+R_{3}}$ . 
E)  $\frac{1}{R}=\frac{1}{R_{1}}+\frac{1}{R_{2}}+\frac{1}{R_{3}}$ . 
A) R = R1 + R2 + R3. 
B)  $R=\frac{R_{1} R_{2}+R_{1} R_{3}+R_{2} R_{3}}{R_{1}+R_{2}+R_{3}}$ . 
C)  $R=\frac{R_{1} R_{2} R_{3}}{R_{1} R_{2}+R_{1} R_{3}+R_{2} R_{3}}$ . 
D)  $\frac{1}{R}=\frac{1}{R_{1}+R_{2}+R_{3}}$ . 
E)  $\frac{1}{R}=\frac{1}{R_{1}}+\frac{1}{R_{2}}+\frac{1}{R_{3}}$ .

Question 20

The wall of a house consists of a slab of concrete (of R-value 0.5) with an insulating board (or R-value 1.5) firmly attached to the inside. The concrete and board are in thermal contact with each other. The temperature inside the house is 20 $\degree$C and outside the house is 0 $\degree$C. Determine the rate at which heat is lost through one square metre of wall (in W).

Accepted Answer

A) 20 
B) 10 
C) 13.3 
D) 40 
E) 2.0 
A) 20 
B) 10 
C) 13.3 
D) 40 
E) 2.0

Two kilograms of water at 100 $\degree$ C is converted to steam at 1 atm. Find the change in internal energy (in J). (Lv = 2.26 *106 J/kg.)

Determine the work done by 5 moles of an ideal gas that is kept at 100 $\degree$ C in an expansion from 1 litre to 5 litres.

In an isobaric process:

A 5-g coin is dropped from a 300-m building. If it reaches a terminal velocity of 45 m/s, and the rest of the energy is converted to heating the coin, what is the change in temperature (in $\degree$ C) of the coin? (The specific heat of copper is 387 J/kg. $\degree$ C.)

We are able to define a mechanical equivalent for heat because:

A child has a temperature of 101 $\degree$ F. If her total cross-sectional area is 2 m², find the energy lost each second (in W) due to radiation, assuming the emissivity is 1. (Assume the room temperature is 70 $\degree$ F.)

A 100-kg student eats an 840-kJ doughnut. To 'burn it off', he decides to climb the steps of a tall building. How high (in m) would he have to climb to expend an equivalent amount of work?

The Earth intercepts 1.27 * 1017 W of radiant energy from the sun. Suppose the Earth, of volume 1.08 * 1021 m3, was composed of water. How long would it take for the Earth at 0 $\degree$ C to reach 100 $\degree$ C, if none of the energy was radiated or reflected back out into space?

A styrofoam container used as a Esky contains a block of ice at 0 $\degree$ C. If 225 grams of ice melts in 1 hour, how much heat energy per second is passing through the walls of the container? (The heat of fusion of ice is 3.33 * 105 J/kg).

Gas in a container increases its pressure from 1 atm to 3 atm while keeping its volume constant. Find the work done (in J) by the gas if the volume is 5 litres.

In a thermodynamic process, the internal energy of a system in a container with adiabatic walls decreases by 800 J. Which statement is correct?

Star A has a radius of 200 000 km and a surface temperature of 6000 K. Star B has a radius of 400 000 km and a surface temperature of 3000 K. The emissivity of both stars is the same. What is the ratio of the rate of energy radiated by Star A to that of Star B?

Five moles of an ideal gas expands isothermally at 100 $\degree$ C to five times its initial volume. Find the heat flow into the system.

A gas expands from A to B as shown in the graph. Calculate the work (in joules) done by the gas. (1 atm= 1.01 *105 N/m².)

The R value of a particular brand of 'pink batt' roof insulation is 3 m² K W-1. If the pink batts are 6cm thick, what is their thermal conductivity (in W m-1 K-1)?

The R-value of an insulating material is the thickness of the material divided by its thermal conductivity. When an insulating material consists of three layers with R-values R1, R2 and R3, the overall R-value of the insulation is given by:

Physics and Measurement

Motion in One Dimension

Motion in Two Dimensions

Forces and Newtons Laws

Further Applications of Newtons Laws

Work, Force and Energy

Conservation of Energy

Linear Momentum and Collisions

Rotational Motion

Energy and Momentum in Rotating Systems

Gravity

Special Relativity

Fluid Statics

Fluid Dynamics

Solids

Oscillatory Motion

Wave Motion

Superposition and Interference

Heat and Temperature

The Kinetic Theory of Gases

The Second Law of Thermodynamics, Heat Engines and Entropy

Filters

Exam 20: Energy Transfer Processes and Thermodynamics

Two kilograms of water at 100 °\degree° C is converted to steam at 1 atm. Find the change in internal energy (in J). (Lv = 2.26 *106 J/kg.)

Determine the work done by 5 moles of an ideal gas that is kept at 100 °\degree° C in an expansion from 1 litre to 5 litres.

In an isobaric process:

A 5-g coin is dropped from a 300-m building. If it reaches a terminal velocity of 45 m/s, and the rest of the energy is converted to heating the coin, what is the change in temperature (in °\degree° C) of the coin? (The specific heat of copper is 387 J/kg. °\degree° C.)

We are able to define a mechanical equivalent for heat because:

A child has a temperature of 101 °\degree° F. If her total cross-sectional area is 2 m2, find the energy lost each second (in W) due to radiation, assuming the emissivity is 1. (Assume the room temperature is 70 °\degree° F.)

A 100-kg student eats an 840-kJ doughnut. To 'burn it off', he decides to climb the steps of a tall building. How high (in m) would he have to climb to expend an equivalent amount of work?

The Earth intercepts 1.27 * 1017 W of radiant energy from the sun. Suppose the Earth, of volume 1.08 * 1021 m3, was composed of water. How long would it take for the Earth at 0 °\degree° C to reach 100 °\degree° C, if none of the energy was radiated or reflected back out into space?

A styrofoam container used as a Esky contains a block of ice at 0 °\degree° C. If 225 grams of ice melts in 1 hour, how much heat energy per second is passing through the walls of the container? (The heat of fusion of ice is 3.33 * 105 J/kg).

Gas in a container increases its pressure from 1 atm to 3 atm while keeping its volume constant. Find the work done (in J) by the gas if the volume is 5 litres.

In a thermodynamic process, the internal energy of a system in a container with adiabatic walls decreases by 800 J. Which statement is correct?

Star A has a radius of 200 000 km and a surface temperature of 6000 K. Star B has a radius of 400 000 km and a surface temperature of 3000 K. The emissivity of both stars is the same. What is the ratio of the rate of energy radiated by Star A to that of Star B?

Five moles of an ideal gas expands isothermally at 100 °\degree° C to five times its initial volume. Find the heat flow into the system.

A gas expands from A to B as shown in the graph. Calculate the work (in joules) done by the gas. (1 atm= 1.01 *105 N/m2.)

The R value of a particular brand of 'pink batt' roof insulation is 3 m2 K W-1. If the pink batts are 6cm thick, what is their thermal conductivity (in W m-1 K-1)?

The R-value of an insulating material is the thickness of the material divided by its thermal conductivity. When an insulating material consists of three layers with R-values R1, R2 and R3, the overall R-value of the insulation is given by:

Physics and Measurement

Motion in One Dimension

Motion in Two Dimensions

Forces and Newtons Laws

Further Applications of Newtons Laws

Work, Force and Energy

Conservation of Energy

Linear Momentum and Collisions

Rotational Motion

Energy and Momentum in Rotating Systems

Gravity

Special Relativity

Fluid Statics

Fluid Dynamics

Solids

Oscillatory Motion

Wave Motion

Superposition and Interference

Heat and Temperature

The Kinetic Theory of Gases

The Second Law of Thermodynamics, Heat Engines and Entropy

Filters

Two kilograms of water at 100 $\degree$ C is converted to steam at 1 atm. Find the change in internal energy (in J). (Lv = 2.26 *106 J/kg.)

Determine the work done by 5 moles of an ideal gas that is kept at 100 $\degree$ C in an expansion from 1 litre to 5 litres.

A 5-g coin is dropped from a 300-m building. If it reaches a terminal velocity of 45 m/s, and the rest of the energy is converted to heating the coin, what is the change in temperature (in $\degree$ C) of the coin? (The specific heat of copper is 387 J/kg. $\degree$ C.)

A child has a temperature of 101 $\degree$ F. If her total cross-sectional area is 2 m², find the energy lost each second (in W) due to radiation, assuming the emissivity is 1. (Assume the room temperature is 70 $\degree$ F.)

The Earth intercepts 1.27 * 1017 W of radiant energy from the sun. Suppose the Earth, of volume 1.08 * 1021 m3, was composed of water. How long would it take for the Earth at 0 $\degree$ C to reach 100 $\degree$ C, if none of the energy was radiated or reflected back out into space?

A styrofoam container used as a Esky contains a block of ice at 0 $\degree$ C. If 225 grams of ice melts in 1 hour, how much heat energy per second is passing through the walls of the container? (The heat of fusion of ice is 3.33 * 105 J/kg).

Five moles of an ideal gas expands isothermally at 100 $\degree$ C to five times its initial volume. Find the heat flow into the system.

A gas expands from A to B as shown in the graph. Calculate the work (in joules) done by the gas. (1 atm= 1.01 *105 N/m².)

The R value of a particular brand of 'pink batt' roof insulation is 3 m² K W-1. If the pink batts are 6cm thick, what is their thermal conductivity (in W m-1 K-1)?