Question

A ball rest on the ground.A boy throws it up vertically.What kind of work is done by (a) boy (b) the gravitational force​

Answer 1

Answer

with

Explanation:

( a )

Work done by the boy is positive workdone. Because, force applied by the boy in the ball is in the same direction that of displacement

○ ↑

Person ↑

( b )

Work done by the gravitational force is negative workdone. Because, the gravitational force is against the ball, which is thrown vertically upwards.

○ ↑ gravity ↓