In Figure 7.7, consider the cart's initial speed to be \(v_{\mathrm{i}}\). Assuming no potential energy is initially stored in the spring, how much potential energy is stored in the spring at the instant depicted in the middle drawing and at the instant depicted in the bottom drawing? Give your answers in terms of \(m, v_{\mathrm{i}}\), and \(v\).

Figure 7.7 Energy conversion during the compression of a spring by a moving cart. v wwwww www K KI K U K U