An object of mass 15 kg is at an elevation of 100 m relative to the surface of the Earth. What is the potential energy of the object, in kJ? If the object were initially at rest, to what velocity, in m/s, would you have to accelerate it for the kinetic energy to have the same value as the potential energy you calculated above? The acceleration of gravity is 9.8 m/s2.

The potential energy of the object is 14.7 kJ

The velocity of the object is 44.27 m/s

Explanation:

Given;

mass of the given object, m = 15 kg

position of the object, h = 100 m

acceleration due to gravity, g = 9.8 m/s²

The potential energy of the object is calculated as;

P.E = mgh

P.E = 15 x 9.8 x 100

P.E = 14,700 J = 14.7 kJ

The velocity of the object if its kinetic energy must equal potential energy;

¹/₂mv² = mgh

v² = 2gh

v = √2gh

v = √(2 x 9.8 x 100)

v = 44.27 m/s

3.2x10^7