A waterfall is 630cm high. What is the change in temperature of a quantity of water that falls from the top to the bottom of the waterfall? (Neglect heat losses to the surroundings, take g as 10 ms-2 and specific heat capacity of weather as 4200J kg-1K-1
N.N.P.C. gas cylinder containing 15kg of cooking gas was left open, and the gas emptied in 3.8 minutes, at an average speed of 20 ms-1. What force was exerted on the gas in the cylinder?
