Physics - W.E.P. Question with Solution | TestHub

Assertion (A): A block of mass $m$ is pushed by a variable force $F(x)=kx$ (where $k$ is a positive constant) on a rough horizontal surface with coefficient of kinetic friction $\mu$. If the block starts from rest at $x=0$ and moves to $x=L$, its final kinetic energy will be $K_f=\frac{1}{2}k{L}^2-\mu mgL$.

Reason (R): The work done by the net force on the block is equal to the change in its kinetic energy, and the work done by a variable force is given by $\int F(x)dx$.