Physics

Worksheet 7- Section 10.2

Thermal Expansion and Energy Transfer

1. Two identical metal rods are at room temperature. One rod is heated by 10 °C, and the other is cooled by 10 °C. How do their new lengths compare?

2. Which exchange process carries thermal energy through boiling water as it heats on top of a stove?

3. Does thermal energy exchange by radiation require a medium (particles of matter) through which the energy is transferred?

4. If you want to exchange a lot of thermal energy by conduction, should you use a conductor or an insulator?

For Problems 5-7, refer to Table 10.1 for the coefficients of thermal expansion.

5. A hole in a copper plate has a diameter of 1.325 cm at 21.00 °C. What is the diameter of the hole at 224.0 °C?

6. A hole in a steel plate has a diameter of 1.166 cm at 23.00 °C. At what temperature is the diameter of the hole equal to 1.164 cm?

7. An aluminum rod changes its length by 0.0032 cm when the temperature changes by 120 °C. What was the initial length of the aluminum rod?