15-67. The \( 50-\mathrm{kg} \) crate \( A \) is released from rest onto the smooth ramp. After it slides down the ramp it strikes the \( 100-\mathrm{kg} \) erate \( B \) that rests against the spring of stiffness \( k=10 \mathrm{kN} / \mathrm{m} \). If the coefficient of restitution between the crates is \( e=0.5 \), determine their velocities just after impact. Also, what is the spring's maximum compression? The spring is originally unstretched.