1. 1.To understand the energy transformations which take place during simple harmonic motion Book Reference : Pages 44-45

2. If we consider an ideal pendulum.... Which form of energy will it have when it is displaced from the equilibrium position at one of the two extremes of oscillation Which form of energy will it have when it is moving through the equilibrium position Which form(s) of energy will it have during the rest of the cycle? How does the total energy change during the whole cycle?

3. It has the “potential to fall” and so gravitational potential energy (E p ) It is moving and so it will definitely have kinetic energy (E k ). At the equilibrium point it cannot “fall further” so only kinetic Everywhere else it is moving and has the potential to fall further & so the energy is a combination of E p & E k The total energy remains unchanged. It alternates between being all E p, a mixture of both & all E k

4. How will this apply to an ideal horizontal SHM system based around springs? How about if the spring arrangement were vertical?

5. Exactly the same, apart from the potential energy would be elastic potential energy stored in the spring rather than gravitational Same conversion between potential and kinetic energy and back again. However, this time the potential would be a combination of gravitational and elastic Sketch a graph of the total energy, Ep & Ek on the same axis as the pendulum oscillates between  A

6. +A -A EkEk EpEp Total Energy Energy displacement

7. If we use information about the energy in the system, and a few “bits” of other information, what other things are we likely to be able to find? Think about the alternative way of approaching SUVAT type problems... For example the skateboarder question

8. We can equate the conservation of energy (ideal world) At extremes  A total energy = E p and E k = 0 Passing through the equilibrium point total energy = E k and E p = 0 In between Total energy = E p + E k This will typically allow us to solve problems with a range of information (E k = ½mv 2 ), (Gravitational  E p = mg  h) and perhaps the potential energy stored in a spring (E p = ½F  L)

9. A system in simple harmonic motion is being damped when energy is being “lost” from the system in oscillation Most obvious is air resistance and friction in the pivot point

10. Next Practical : Spring with “parachute” experiment

11. Written HW assignment... Complete this topic yourself! Write a couple of pages explaining the following: Natural frequency, periodic force, forced oscillations, applied frequency, resonance. Try and find example experiments, real-world examples. Include some charts or graphs and use keywords such as phase difference, amplitude