1A steel plate and a ceramic plate, a wooden chair and a plastic chair, sand and soil, and a steel vessel and a glass are all kept in the sun together for about 15 to 20 minutes. Which one of each group heats faster?
2What is the effect of the heat on each of these groups of substances?
3200 g of water and 400 g of water at the same temperature are heated by sources of the same capacity. Which absorbs more heat energy when its temperature is increased by 10 °C?
4The 400 g of water is heated until its temperature rises by 10 °C and then by 20 °C. In which case is more heat absorbed? What conclusion can be drawn from both activities?
5Calculate the amount of heat energy consumed by an electric kettle to heat 5 kg of water at 10 °C up to 100 °C. (Specific heat capacity of water = 4200 J/kg°C)
6Calculate the final temperature when 5 kg of water at 100 °C is mixed with 15 kg of water at 15 °C for bathing. Take the heat lost to the surroundings as negligible.
7Define specific heat capacity and write its SI unit.
8The specific heat capacity of ice is 2100 J/kg°C and that of water is 4200 J/kg°C. What do these values mean?
9How much heat is needed to raise the temperature of 2 kg of aluminium from 20 °C to 70 °C? (Specific heat capacity of aluminium = 884 J/kg°C)
10Why is water used as a coolant in the radiator of a car?
11Why is a hot water bag used to soothe muscular pain?
12Explain how a sea breeze is formed.
13Explain how a land breeze is formed at night.
14How does the water in our body help keep our body temperature steady?