Question

If a man holds an object of mass 20kg at 1.3m then the value of work done is?

Answer 1

Answer:

254.8 j

Explanation:

we know, w= mgh = 20×9.8 × 1.3 = 254.8 j

Answer 2

The value of work done is 254.8 J

When the man holds the object at a height, some amount of work is done by him under the effect of gravity. This work done is stored as the potential energy within the body.

We know, potential energy = m× g× h

Where, m= mass of the object

g = acceleration due to gravity

h = height at which the object is hold/ placed.

Given, m= 20 kg

h = 1.3 m

So, the amount of potential energy = 20 × 9.8 × 1.3 J [By taking g= 9.8 m/s²]

                                                           = 254.8 J

The value of work done is 254.8 J.