A rock falls off the top of a cliff of height h. Figure 1 shows the rock falling.
The Earth exerts a force of 150 N on the rock.
rock
cliff
h
150N
Figure 1
The work done by this force when the rock falls from the top to the bottom of the cliff is 2700 J.
(1) Calculate the height, h, of the cliff.

Asmall electric heater, immersed in 80g of water in a calorimeter of 40j/k raises the temperature from 10.5 degree celsius to 25 degree celsius in 12 minutes. using the same apparatus with 50g of oil instead of water, it is found that the temperature of oil rises from 7 degree celsius to 27 degree celsius in 10 minutes. find specific heat capacity of the oil.