The temperature of the water at the bottom of a waterfall is greater than the temperature of the water at the top.
The energy in the gravitational potential store of the water at the top is transferred to the thermal store of the water at the bottom.
The specific heat capacity of water is 4200 J/(kg⋅∘C)4200\text{ J}/(\text{kg}\cdot{}^\circ\text{C})4200 J/(kg⋅∘C) and the acceleration due to gravity is g=9.8 m/s2g = 9.8\text{ m/s}^2g=9.8 m/s2.
What is the temperature difference for a waterfall of height 45 m?
0.011 ∘C0.011\ ^\circ\text{C}0.011 ∘C
0.105 ∘C0.105\ ^\circ\text{C}0.105 ∘C
1.1 ∘C1.1\ ^\circ\text{C}1.1 ∘C
9.5 ∘C9.5\ ^\circ\text{C}9.5 ∘C
119 exam-style questions on CIE IGCSE Physics 2.2.2a Internal energy and temperature. Each one has a worked solution and a mark scheme showing where the marks go.