Question

A ball of mass 2 kg is dropped from a
height .what is of work done by
weight in 2 sec after the ball is dropped​

Answer 1

Explanation:-

m = 2 kg

t = 2 s

u = 0 m/s

To find :-

The work done by gravity.

Solution:-

First , we have to find the height covered by ball.

• Using equation of motion.

→$h = ut + \dfrac{1}{2}gt^2$

→$h = 0 \times t + \dfrac{1}{2}\times 10 \times (2)^2$

→$h = \dfrac{1}{2}\times 10 \times 4$

→$h = 20 m$

Height covered by ball is 20 m.

Now,

The work done by gravity is :-

→$W = mgh$

→$W = 2 \times 10 \times 20$

→$W = 400 J$

hence,

The work done by gravity is 400J.