Unit 6 - Forces that Accelerate

Today we started on Unit 6, and forces that accelerate. We spent a lot of time discussing one type of problem in particular, involving elevators. When elevators move at constant velocity, they have an acceleration of zero, like any other object moving at a constant velocity. But when it does accelerate, the acceleration is directly related to the net force on the elevator, which includes the weight of the elevator, a force going down, and the tension cable pulling the elevator up. However, elevators aren't always accelerating. They mostly accelerate at the beginning and the end of their journey, with a constant velocity in between.

If there's a person inside the elevator, as there often in, then the forces that are affecting them would be their weight and the normal force of the elevator floor beneath them. When the elevator is either moving at a constant velocity or at rest, the net force on the person would be zero. When the elevator is accelerating, the person is no longer in equilibrium, and either has a greater normal force or force of gravity acting upon them, causing them to feel either heavier or lighter depending on which direction the elevator is heading.

Here's a picture of some of my notes from today's discussion:

They're a little bit of a mess, because let's be honest, my understanding of this is sketchy at best.