I've been reading about a situation on the conservation of energy: A spring-loaded toy gun is used to shoot a ball of mass m straight up in the air. View Figure The spring has spring constant k. If the spring is compressed a distance x_0 from its equilibrium position and then released, the ball reaches a maximum height h_max (measured from the equilibrium position of the spring). There is no air resistance, and the ball never touches the inside of the gun. Assume x_o is greater than h Now my question to this is that: Is mechanical energy conserved because no nonconservative forces perform work on the ball and do nonconservative forces act in this situation after the ball is released at all? and do the forces of gravity and the spring have potential energies associated with them? As you can tell I don't really have a great grasp on these concepts, so would anyone like to enlighten me please???? thanks so much!!