1. In which direction does thermal energy (heat) flow?

2. The rate at which an object transfers thermal energy depends on what?

3. Why are cooling fins thin and flat?

4. During the cold weather, birds can often appear bigger than they do when the weather is warm. Which of the following is the most likely explanation?

5. At the back of a refigerator there is a condenser which is designed to change the hot refrigerant gas into a liquid. The tubes of the condenser are attached to hundreds of small metal 'fins'. Why?

6. A student investigated the rate of heat transfer from four identical containers of water. The water was heated to different temperatures (shown below). She then placed containers B and C in a freezer at -5^oC and containers A and D in a room with a temperature of 20^oC, and noted the temperature drop during the first two minutes of cooling. Which of the following statements is correct?

Container D: 80^oC

7. Which of the following statements is false?

8. Based on the information that 'the chemical called ether evaporates much faster than water', which of the following statements is true?

9. During the winter, moisture often condenses on the inside of windows of old houses. This rarely happens during the summer. Which of the following is likely to be the main reason for this?

10. A student investigated the rate of heat transfer from four identical containers of water. The water was heated to different temperatures (shown below) and she noted the temperature drop during the first two minutes of cooling. Which answer puts them in the correct order, from lowest rate to highest rate?
Container A: 35^oC
Container B: 55^oC
Container C: 45^oC
Container D: 80^oC