Unit 6: Rotation and Simple Harmonic Motion
There are many different types of motion that physicists study. Plenty of objects in the real world have one and two-dimensional motions like those we have studied so far in this course (cars and cannonballs, for example). But there are many other classes of motion.
We say that objects "translate" when they move along straight line paths, but they "rotate" when the spin around an internal axis. Many objects, like the Earth or a gyroscope, rotate around internal axes, so it's important to understand how these rotations can be described. Click the play button above to see the illusion of motion that accompanies the rotation of a disk created for an 19th century invention called a phenakistoscope.
Additionally, we can mathematically describe the many objects in our world that undergo "periodic" motion, ie., repetitive motion or oscillations. For example, objects that dangle from springs, the pistons in the cylinders of your car, or the mass on the end of a simple pendulum, all undergo a type of oscillation called "Simple Harmonic Motion." In the case of a simple pendulum the motion is only approximate SHM (we will see why this is true shortly). This sounds like a lot to take in, but if you internalize it one concept at a time, I'm sure you will get into the swing of it...no pun intended.
Suggested timeframe: 5 weeks
•The concept of force can be used to describe the interactions between objects in systems or between systems themselves.
•Systems can change due to interactions with other systems.
•Laws of conservation of certain properties of systems restrict the manner in which systems can change due to interactions.