The heat exchanger radiates thermal energy at the rate of 2500 kJ/h for each square meter of its surface area. Determine how many joules (J) are radiated within a 5-hour period.

On a summer day, the mean solar irradiance received at a lake was 500 W/m^ 2 over 25 days (consider the day length to be 8 hours). If 80% of the energy is used to vaporize water, how large could the depth of evaporation be?

When 1 cu ft of natural gas is burned, 1,050 Btu of heat are produced. In oneday, a building uses 761,250 Btu of heat. How many cubic feet of gas areburned?