Answer to Question #90399 in Mechanics | Relativity for Peter

Question

Niagara falls are 50m high. calculate the potential energy of 0.1 cubic meter of water at the top relative to the bottom. density of water is 1000 kg m^-3. take g= 10m/s^2

Answer 1

Potential energy is:

$$E=mgh$$

Mass:

$$m=\rho*V$$

then:

$$E=\rho Vgh=1000\times 0.1\times 10 \times 50 = 50000 J = 50 kJ$$