Question

A ball of mass 1kg is at a height of 20m above the ground. In free fall, find(i) speed of the ball when it reaches the ground and (ii) work done by the gravitational force. (Take g = 10ms).

Answer 1

..... Now get your brainliest answer......

work done=mgh=1kg*20m*10m/squ..=200joule.

from work and energy theory.
velocity =√2gh=√2*10*20=√400=20m/s.

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Answer 2

Answer:Speed is 20m/s and work done is 200 joule

Explanation:

1) To find speed use the equation

v^2-u^2 = 2as

For gravitational force use g insted.

of and h instead of h

So the equation becomes

v^2-u^2 = 2gh

v^2-0^2 = 2*10*20

v^2 = 400

v = √400

v = 20

So v = 20m/s is the speed

2) work done = mgh

Work done = 1*10*20

Work done = 200

So the work done is 200 joule

Hope it works✌