Question

a body of mass 10 kg slide down an incline plane from rest Its Height from the ground level is 10 metre the incline plane is not smooth when the water reaches the ground it 14 M per second square is then how much work done against friction (g =10 )

Answer 1

Hope this helps. Ask for any doubts in this.

Answer 2

Answer:

The work done against the friction is -20 J

Explanation:

The height at which the body is initially above the ground is h=10 m

The mass of the body is m=10 kg

The inclined surface is rough

The speed of the body is v=14 m/s

The initial energy in the body is

$U=mgh\\U=10\times 10\times 10\\U=1000\ J$

The final energy in the body is

$KE=\dfrac{1}{2}mv^2\\KE=\dfrac{1}{2}\times 10\times 14^2\\KE=980$

The change in energy in the body is

$\Delta E=KE-U\\\Delta E=980-1000\\\Delta E=-20\ J$

We know that the change in energy is equal to the work done

So,

$W=\Delta E\\W=-20\ J$