Question

A 75-kg refrigerator is located on the 70th floor of a skyscraper (300 meters above the ground). What is the potential energy of the refrigerator?

Answer 1

potential energy is mass * acceleration due to gravity * height which is 75 * 300 *10 = 225000N

Answer 2

Potential energy is the stored energy in an object due to its position with respect to some reference (normally ground).

We will use the formula:

P.E. = mgh

Where P.E. is the potential energy, m is the mass of the body , h is the height of the body's displacement and g is the acceleration due to gravity which is constant on earth and is 9.8 m/s²

P.E. = 75kg × 9.8m/s² × 300 m

P.E. = 22,500kgm × 9.8m/s²

P.E. = 220,500 Nm

P.E. = 220,500 joules