Question:
Figure (8-E7) shows a spring fixed at the bottom end of an incline of inclination $37^{\circ}$. A small block of mass $2 \mathrm{~kg}$ starts slipping down the incline from a point $4.8 \mathrm{~m}$ away from the spring. The block compresses the spring by $20 \mathrm{~cm}$, stops momentarily and then rebounds through a distance of $1 \mathrm{~m}$ up the incline. Find
(a) the friction coefficient between the plane and the block and
(b) the spring constant of the spring. Take $g=10 \mathrm{~m} / \mathrm{s}^{2}$.
Solution: