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