Question

calculate the potential energy of a body of mass 5kg, raised 3m, above the ground. (g=10ms-2)​

Answer 1

Explanation:

Mass of the body (m) = 5 kg

Height (h) = 3 m

We know that,

Potential energy of a body (PE) = mgh

Therefore,

PE of the body = 5 * 3 * 10 = 150 kg m²/s² = 150 J

$\boxed{\rm PE \: of \: the \: body \: is \: 150 J \: or \: 150 \: kg \: m²/s² }$

Derivation of Potential energy:-

We know that

W = Force * Displacement

We we catch a ball in mid air at an height h from the earth's surface

Then, the force acting on the ball is the weight force

Let us assume that the mass of the ball is m

Then, the weight force acting on the ball = mg

W = mg * h

∴ W = mgh

As the work done is equal to mgh which is gained by the object, potential energy PE is given as:

PE = mgh