I'm having trouble solving for d in problem 8-35. I'm guessing that it has something to do with work, but am not able to correctly solve for the value. Do you have any hints?
At the initial moment (when the block is released), the kinetic energy of the block is zero. At the moment when the spring is maximally compressed, the block is temporarily motionless, so at that 'final' moment the kinetic energy is zero. Write down the initial potential energy of the combined system of the block plus the spring and set that equal to the final potential energy of the block plus the spring. This should give you an equation with exactly one unknown, d.