A block of mass m is attached to a spring with spring constant k, as shown in the figure. The equilibrium position of the spring is x = 0. The spring is compressed over a distance x, and then released. The block slides over a frictionless surface. Foooooood m x = -X x = 0 X = Xf (a) State the Work - Kinetic Energy Theorem (in formula form), and identify all symbols in the equation. (3 marks) (2 marks) (b) Find an expression for the velocity of the block at x = 0. (2 marks) (c) Find an expression for the maximum extension xf of the spring. (d) The surface on which the block slides is replaced with a surface with a coefficient of kinetic friction k. When the block is again released at x = -x, it is observed that the block stops at x = 0 exactly. Find the relationship between k and k- (3 marks)