A0.50-kg mass is placed on the end of a vertical spring that has a spring constant of 75 n/m and eased down into its equilibrium position.
(a) determine the change in spring (elastic) potential energy of the system.
(b) determine the system’s change in gravitational potential energy.

Awater slide of length l has a vertical drop of h. abby's mass is m. an average friction force of magnitude f opposes her motion. she starts down the slide at initial speed vi. use work-energy ideas to develop an expression for her speed at the bottom of the slide. then evaluate your result using unit analysis and limiting case analysis. express your answer in terms of the variables h, m, l, vi, f and appropriate constants. vf v f