# Thermodynamics test questions

TEST   THERMODYNAMICS

1. Can temperature be assigned to a vacuum? Explain.

2. Convert the following Kelvin temperatures to Celsius temperatures.

a. 135 K         b. 185 K     c. 475 K

3. Can you add thermal energy to an object without increasing its temperature? Explain.

4. When an object freezes, does it absorb or release energy?

5. How much heat is needed to raise the temperature of 50.0 g of water from 4.5°C to 83.5°C?

6. A 100-g mass of tungsten at 100.0°C is placed in 200 g of water at 20.0°C. The mixture reaches equilibrium at 21.6°C. Calculate the specific heat of tungsten.

7. Which is larger, a Celsius degree or a kelvin?

8. If 100 J of heat is added to a system that does no external work, by how much is the internal energy of that system raised?

9. If 100 J of heat is added to a system that does 40 J of external work, by how much is the internal energy of that system raised?

10. What is the physicist’s term for measure of amount of disorder?

11. When heat flows from a warm object in contact with a cool object, do both objects undergo the same amount of temperature change?

12. Could you cool a kitchen by leaving the refrigerator door open?

13. What happens to the density of a quantity of gas when its temperature is decreased and its pressure is held constant?

14. According to the second law of thermodynamics, is the universe moving to a more ordered state or to a more disordered state?

15. Is the total energy of the universe becoming more unavailable with time? Explain.

16. Water put into the freezer compartment of your refrigerator goes to a state of less molecular disorder when it freezes.(Why?) Is this an exception to the entropy principle? Explain.

17. A 2.2-kg block of ice slides across a rough floor. Its initial velocity is 2.5 m/s and its final velocity is 0.50 m/s. How much of the ice block melted as a result of the work done by friction?

18. Common brick is about 1.8 times denser than water. What is the apparent weight of a 0.20 m³ block of bricks under water?

19. A girl is floating in a freshwater lake with her head just above the water. If she weighs 610 N, what is the volume of the submerged part of her body?

20. Which of the following displaces more water when it is placed in an aquarium?

-a 1.0-kg block of aluminum or a 1.0-kg block of lead?

-a 10-cm³ block of aluminum or a 10-cm³ block of lead?

21. According to Pascal’s principle, what happens to the pressure at the top of a container if the pressure at the bottom is increased?

22. How does the arrangement of atoms in a crystalline substance differ from that in an amorphous substance?

23. Show that a pascal is equivalent to a kg/m.s²

24. What is the apparent weight of a rock submerged in water if the rock weighs 45 N in air and has a volume of 2.1 liters?

25. An extraterrestrial scientist invents a temperature scale such that water freezes at -75°E and boils at 325°E, where E stands for an extraterrestrial scale. Find an equation that relates temperature in °E to temperature in °C.