Question

18. An object of mass m is sliding down a hill of arbitrary shape and after travelling a certain horizontal path stops because of friction. The work done that a force must perform to return the object to its initial position along the same path would be:- m h m (2) mgh (1) 0 (3) 2mgh (4) None of these​

Answer 1

Explanation:

Correct option is

A

mgh

h

′

=h

△PE=mg△h

now work done by friction =△PE

friction=f

s

now work done by f

s

=△PE

f

s

.d=mgh

So the work done against gravity to make the body reach its highest

Answer 2

Hope this helps u : )