Posted by Jennifer on .
Your whole family has taken showers before you, dropping the temperature in the water heater to 18 degrees Celsius. If the water heater holds 150 kg of water, how much energy will it take to bring it to 50 degrees Celsius? If the energy is supplied by a 5 kW electric heating element, how long will it take?

Physics 
drwls,
Q = M*C*deltaT = 150 kg* 4184 J/kg*C*32 C
= ? J
Time = Q (J) /5000 J/s
The answer will be in seconds