lecture 9- thermodynamics chapter 18jn511/lectures/lecture9slides.pdflecture 9- thermodynamics...

Exam 2 0th Law of Thermodynamics Expansion/Contraction Heat 1st Law of Thermodynamics Heat Transfer Extra Questions

Lecture 9- ThermodynamicsChapter 18

Prof. Noronha-HostlerPHY-124H HONORS ANALYTICAL PHYSICS IB

Phys- 124HMarch 30th, 2018

1 / 16

Test- Curve renormalized by 85

2 exams questions were mislabeled, grades shifted (could bepositive or negative)

2 / 16

May 8th, 2018 at 8 AM!!

3 / 16

Triple Point

4 / 16

Corresponding temperatures

5 / 16

6 / 16

7 / 16

18.5.2. Three thermometers are used to measure the temperature inside a closed, insulated box. Thermometer A is calibrated in Fahrenheit degrees, thermometer B in Celsius degrees, and thermometer C in kelvins. When the thermometers reach thermal equilibrium with the interior of the box, B reads 40 C and C reads 233 K. Which one of the following statements is necessarily true?

a) Thermometer C should read 233 K.

b) Thermometer A must read –40 °F.

c) If the temperature of the interior of the box is increased until A reads 20 F, thermometer B will read 10 C.

d) Thermometer B should read 77 C.

e) If the temperature of the interior of the box is increased until C reads 293 K, thermometer A will read 36 F.

18.5.2. Three thermometers are used to measure the temperature inside a closed, insulated box. Thermometer A is calibrated in Fahrenheit degrees, thermometer B in Celsius degrees, and thermometer C in kelvins. When the thermometers reach thermal equilibrium with the interior of the box, B reads 40 C and C reads 233 K. Which one of the following statements is necessarily true?

a) Thermometer C should read 233 K.

b) Thermometer A must read –40 °F.

c) If the temperature of the interior of the box is increased until A reads 20 F, thermometer B will read 10 C.

d) Thermometer B should read 77 C.

e) If the temperature of the interior of the box is increased until C reads 293 K, thermometer A will read 36 F.

Changes with temperature

8 / 16

18.6.4. Which one of the following statements is the best explanation for the fact that metal pipes that carry water often burst during cold winter months?

a) Both the metal and the water expand, but the water expands to a greater extent.

b) Water contracts upon freezing while the metal expands at lower temperatures.

c) The metal contracts to a greater extent than the water.

d) The interior of the pipe contracts less than the outside of the pipe.

e) Water expands upon freezing while the metal contracts at lower temperatures.

18.6.4. Which one of the following statements is the best explanation for the fact that metal pipes that carry water often burst during cold winter months?

a) Both the metal and the water expand, but the water expands to a greater extent.

b) Water contracts upon freezing while the metal expands at lower temperatures.

c) The metal contracts to a greater extent than the water.

d) The interior of the pipe contracts less than the outside of the pipe.

e) Water expands upon freezing while the metal contracts at lower temperatures.

Transfer of Heat

9 / 16

Measuring Heat

10 / 16

18.7.1. Why is water often used as a coolant in automobiles, other than the fact that it is abundant?

a) Water expands very little as it is heated.

b) The freezing temperature of water has a relatively large value.

c) The specific heat of water is relatively small and its temperature can be rapidly decreased.

d) The specific heat of water is relatively large and it can store a great deal of thermal energy.

e) Water does not easily change into a gas.

18.7.1. Why is water often used as a coolant in automobiles, other than the fact that it is abundant?

a) Water expands very little as it is heated.

b) The freezing temperature of water has a relatively large value.

c) The specific heat of water is relatively small and its temperature can be rapidly decreased.

d) The specific heat of water is relatively large and it can store a great deal of thermal energy.

e) Water does not easily change into a gas.

Piston

11 / 16

Path Dependence

12 / 16

Special Cases

13 / 16

18.3.1. Which one of the following situations is described by the zeroth law of thermodynamics?

a) An air conditioner transfers heat from the inside of a house to the outside of the house.

b) A monatomic gas is held within a container that has a moveable piston. The gas absorbs heat from the surroundings and expands at constant pressure and temperature.

c) A container with adiabatic walls holds boiling water. A thermometer is calibrated by inserting it into the boiling water and allowing it to reach thermal equilibrium with the water.

d) A pot contains oil at 175 C. When frozen sliced potatoes are dropped into the oil, heat is transferred from the oil to the potatoes.

e) A physicist removes energy from a system in her laboratory until it reaches a temperature of 3 1010 K, a temperature very close to (but still greater than) absolute zero.

18.3.1. Which one of the following situations is described by the zeroth law of thermodynamics?

a) An air conditioner transfers heat from the inside of a house to the outside of the house.

b) A monatomic gas is held within a container that has a moveable piston. The gas absorbs heat from the surroundings and expands at constant pressure and temperature.

c) A container with adiabatic walls holds boiling water. A thermometer is calibrated by inserting it into the boiling water and allowing it to reach thermal equilibrium with the water.

d) A pot contains oil at 175 C. When frozen sliced potatoes are dropped into the oil, heat is transferred from the oil to the potatoes.

e) A physicist removes energy from a system in her laboratory until it reaches a temperature of 3 1010 K, a temperature very close to (but still greater than) absolute zero.

Transfer

14 / 16

Thermal Radiation

15 / 16

Extra Questions

16 / 16

18.6.1. An artist wishes to insert a gold pin into a hole in an iron sculpture and have it held permanently. The pin is slightly larger than the hole. The coefficient of linear thermal expansion of gold is slightly larger than that of iron. Consider the following options: (1) increase the temperature of the pin and the sculpture by the same amount, (2) decrease the temperature of the pin and the sculpture by the same amount, (3) increase the temperature of the pin and decrease the temperature of the sculpture, and (4) decrease the temperature of the pin and increase the temperature of the sculpture. Which of the choices would most likely accomplish the artist’s task?

e) 2 and 4

18.6.1. An artist wishes to insert a gold pin into a hole in an iron sculpture and have it held permanently. The pin is slightly larger than the hole. The coefficient of linear thermal expansion of gold is slightly larger than that of iron. Consider the following options: (1) increase the temperature of the pin and the sculpture by the same amount, (2) decrease the temperature of the pin and the sculpture by the same amount, (3) increase the temperature of the pin and decrease the temperature of the sculpture, and (4) decrease the temperature of the pin and increase the temperature of the sculpture. Which of the choices would most likely accomplish the artist’s task?

e) 2 and 4

18.10.2. The internal energy of a system increases during some time interval. Which one of the following statements concerning this situation must be true?

a) The increase in internal energy indicates that work was done on the system.

b) The increase in internal energy indicates that heat was added to the system.

c) The increase in internal energy indicates that work was done by the system.

d) The increase in internal energy indicates that heat was removed from the system.

e) The information given is insufficient to indicate the reason for the increase.

18.10.2. The internal energy of a system increases during some time interval. Which one of the following statements concerning this situation must be true?

a) The increase in internal energy indicates that work was done on the system.

b) The increase in internal energy indicates that heat was added to the system.

c) The increase in internal energy indicates that work was done by the system.

d) The increase in internal energy indicates that heat was removed from the system.

e) The information given is insufficient to indicate the reason for the increase.

18.6.2. The length of an aluminum pendulum in a certain clock is 0.2480 m on a day when the temperature is 23.30 C. This length was chosen so that the period of the pendulum is exactly 1.000 s. The clock is then hung on a wall where the temperature is 5.00 C and set to the correct local time. Assuming the acceleration due to gravity is the same at both locations, by how much time is the clock incorrect after one day at this temperature?

a) 69.3 s

b) 115 s

c) 87.2 s

d) 31.0 s

e) 11.5 s

18.6.2. The length of an aluminum pendulum in a certain clock is 0.2480 m on a day when the temperature is 23.30 C. This length was chosen so that the period of the pendulum is exactly 1.000 s. The clock is then hung on a wall where the temperature is 5.00 C and set to the correct local time. Assuming the acceleration due to gravity is the same at both locations, by how much time is the clock incorrect after one day at this temperature?

a) 69.3 s

b) 115 s

c) 87.2 s

d) 31.0 s

e) 11.5 s

18.6.3. A rod of length L is heated so that its temperature increases by T. As a result, the length of the rod increases by L. The rod is then cut into two pieces, one of length L/3 and one of length 2L/3. What is the ratio of the change in length of the rod of length 2L/3 to L of the original rod when its temperature is increased by T?

a) 1/3

b) 2/3

d) 3/2

18.6.3. A rod of length L is heated so that its temperature increases by T. As a result, the length of the rod increases by L. The rod is then cut into two pieces, one of length L/3 and one of length 2L/3. What is the ratio of the change in length of the rod of length 2L/3 to L of the original rod when its temperature is increased by T?

a) 1/3

b) 2/3

d) 3/2

lecture 9- thermodynamics chapter 18jn511/lectures/lecture9slides.pdflecture 9- thermodynamics...

Documents