### Physics 20

The most common way of describing simple harmonic motion, or ideal oscillatory motion, is by using calculus, since it is easiest to describe continuously changing velocity and acceleration in this way. As well, in order to best explain the oscillating nature of simple harmonic motion, some calculus is needed. However, using forces and energy, two concepts you should be very familiar with, many of the same conclusions can be reached.

It is assumed for the study of simple harmonic motion that no energy is lost due to, for example, heat or air resistance, and that no external forces, such as friction, are present. In reality, it is very difficult to provide an environment that exactly satisfies those conditions, and at least some small amounts of friction and air resistance will be present. However, we make these so-called simplifying assumptions because it makes the equations we need to work with managable.

As we proceed through this module, we will look at how forces and energy can be used to describe different aspects of the motion of the mass. We will also look at the period and frequency of the system and use a couple equations for displacement that you have likely already seen. Throughout the module, there are exercises to ensure you have a good understanding of the material being covered. Use the simulator to help visualize your work. In many cases, the answer can be discovered by using the simulator, but it is important to complete the work by hand as well. After all, if you are examined on this material, you will not have access to the simulator.