20. Heat and Temperature

How much heat must be removed from 0.7 kg of water at 23°C to cool it to 0°C and completely freeze it?

"(II) High-altitude mountain climbers do not eat snow, but always melt it first with a stove. To see why, calculate the energy absorbed from your body if you 

(b) melt 1.0 kg of -15°C snow using a stove and drink the resulting 1.0 kg of water at 2°C, which your body has to warm to 37°C."

(II) An iron boiler of mass 180 kg contains 710 kg of water at 18°C. A heater supplies energy at the rate of 58,000 kJ/h. How long does it take for the water

(b) to all have changed to steam?

Calculate what will happen when 1000 J of heat is added to 100 grams of

(c) water at 10°C