Serway & Jewett — Conservation of Energy: Problem 35

A horizontal spring attached to a wall has a force constant of \(k = 850\text{ N/m}\). A block of mass \(m = 1.00\text{ kg}\) is attached to the spring and rests on a frictionless, horizontal surface as in Figure P8.35. (a) The block is pulled to a position \(x_i = 6.00\text{ cm}\) from equilibrium and released. Find the elastic potential energy stored in the spring when the block is \(6.00\text{ cm}\) from equilibrium and when the block passes through equilibrium. (b) Find the speed of the block as it passes through the equilibrium point. (c) What is the speed of the block when it is at a position \(x_i/2 = 3.00\text{ cm}\)? (d) Why isn't the answer to part (c) half the answer to part (b)?