Question

a block of mass 1 kg is projected initially with velocity 10 metre per second on a rough inclined surface the block moves up and comes back to its initial position and stops find the work done by the frictional force​

Answer 1

It's too simple dear

Work done = change in kinetic energy

Since Gravitational force is a conservative force so work done by it in a closed path is zero

So only friction force works here

Wf = 1/2mV^2 - 1/2mU^2

Here V = final velocity = 0

And U = initial velocity = 10 m/s

So

Wf = 0 - 1/2* 1 kg * (10 m/s) ^2

= - 50 J

Answered by an IIT JEE ASPIRANT and all India mathematics OLYMPIAD TOPPER in class 10th