Explanation:
It is given that,
Mass of the box, m = 10 kg
Force with which the box is pulled, F = 50 N
It is moved a distance of 4 m
Force of friction acting on the box, f = 20 N
We need to find the initial kinetic energy the box have. It is clear that the box is at rest initially. As there is no motion in the box at that time. The formula for the kinetic energy of the box is given by :
[tex]E_k=\dfrac{1}{2}mv^2[/tex]
As v = 0
[tex]E_k=0[/tex]
So, the initial kinetic energy of the box is 0. Hence, this is the required solution.
