Question

A body of mass 100 kg is lifted up by 10 m. Find 1 . The amount of work energy 2. Potential energy of the body at that height (g= 10 m/s)

Answer 1

Given,

Mass m = 100 kg

Height h = 10 m

g = 10 m/s²

1) Work done = mgh

= 100 * 10 * 10

= 10000 J Ans.

2) Potential energy = Work done

= 10000 J Ans.

Answer 2

Given:

• Mass of body = 100 kg
• Height gained = 10 metres

To find:

• Work done ?
• Gravitational Potential Energy?

Calculation:

First of all, when the operator is raising the object, the work done gets converted to potential energy of the object. This is because gravitational force is a conservative force .

So, the work is equal to potential energy :

$\therefore \:W = PE = m \times g \times h$

$\implies \:W = PE = 100 \times 10 \times 10$

$\implies \:W = PE = 10000 \: joule$

$\implies \:W = PE = 10 \: kilojoule$

So, the work done and potential energy both is equal to 10 kilo-joule.