A low-friction track is set up with a spring on the right end. In the middle of the track, a \(2.0-\mathrm{kg}\) cart moving to the right at \(5.0 \mathrm{~m} / \mathrm{s}\) overtakes a \(3.0-\mathrm{kg}\) cart moving to the right at \(2.0 \mathrm{~m} / \mathrm{s}\). After the collision, the \(2.0-\mathrm{kg}\) cart is moving at \(1.7 \mathrm{~m} / \mathrm{s}\).

(a) What is the coefficient of restitution of the collision?

(b) How much energy is stored in the spring when it is at its maximum compression after the collision?