Question

A water fall is 100m high and the difference in temperature between the water at the top and that at the bottom is 0.24K obtain a value for the specific heat capacity of water

Answer 1

Explanation:

potential energy = mass x gravitational force x height (E = mgh),

And assuming that this is a conservative system where there is no energy loss (to the surroundings, air resistance, etc), we can therefore equate:

Loss of gravitational potential energy = gain in molecular kinetic energy of water

(Temperature, is fundamentally the measurement of kinetic energy of the molecules in a body)

hence,

mgh = specific heat capacity x change in temperature x mass

gh = specific heat capacity x change in temperature

10 x 100 = specific heat capacity x 0.24

1000/0.24 = specific heat capacity

specific heat capacity = 4170 (to 3 significant figures)