I have a test soon and I don't get this topic! Here are two questions I'm having trouble with: 1. A simple harmonic oscillator has total energy of E. a) Determine the kinetic and potential energies when the displacement is (1/2)A. A = amplitude. b) For what value of displacement does the kinetic energy equal the potential energy? 2. Please refer to this picture: http://img404.imageshack.us/img404/1311/shmlh9.jpg [Broken] A cart of mass 3 kg is held between two stretched springs as shown. A force of 60N moves the cart 0.10m from its equilibrium position. It's then released and allowed to vibrate. a) How much work was required to move the cart 0.1m? b) Calculate the frequency of the vibration. c) What is the velocity of the cart as it moves through the equilibrium position? I'm not asking for you to do my hw. I just really don't understand the equations and when to use them and how they're derived.