A block of mass 2.0 kg kept at rest on an inclined plane

A block of mass $2.0 \mathrm{~kg}$ kept at rest on an inclined plane of inclination $37^{\circ}$ is pulled up the plane by applying a constant force of $20 \mathrm{~N}$ parallel to the incline. The force acts for one second. (a) Show that the work done by the applied force does not exceed $40 \mathrm{~J}$. (b) Find the work done by the force of gravity in that one second if the work done by the applied force is $40 \mathrm{~J}$.

(c) Find the kinetic energy of the block at the instant the force ceases to act. Take $g=10 \mathrm{~m} / \mathrm{s}^{2}$.