Warm-Up
Section 1
00:00:00TEACHER: What's the relationship between potential energy and kinetic energy? Look at the picture of our ball. It's been thrown, it's lifted up to its highest point, and it starts to come back down. Does it slow down because it's run out of energy at the top of its bounce?
00:00:19And if so, well, what happens to that energy? In this lesson, we're are going to look at what happens and how the energy changes as an object is in motion so that you can answer the question, what is the relationship between potential energy and kinetic energy.
Section 2
00:00:00TEACHER: Now, lesson goals, or what do we want to achieve? We are going to want to explore the differences between potential and kinetic energy. In order to do that, we need to calculate the potential energy in a system and calculate the kinetic energy in a system. And then we're going to explain how energy is
00:00:22transferred in a moving system. To do that, you'll need some words. And here they are. They're system, transformation, kinetic energy, and potential energy. It's a really good opportunity for you to put these in your e-notes. Use your glossary to look up the definition.
00:00:44Don't forget to have them in mind as you move through this lesson so that you can see how they're used. Now, just before we look at the relationship between potential and kinetic energy, let's review what we know about energy itself. Energy is the ability to do work. And that work involves the transfer of energy from one object to another.
00:01:08Let's look at the photograph. This ball on the left is just about to hit these. And that will create motion. We know that that's work. So the ball is transferring the energy and creating work. We know that energy comes in various forms. There's chemical, which is stored in bonds. There's electrical, which is associated with electrical
00:01:33charges, things like lightning and static electricity. Mechanical energy, which is associated with both position and motion. Thermal energy, which is associated with motion in atoms. And potential and kinetic energy, which are the two kinds of energy we are going to concern ourselves with in this lesson particularly.
Instruction
Section 1
00:00:00TEACHER: What is the relationship between potential energy and kinetic energy? We've looked at several different forms of energy itself. Now let's look at the photographs. The train of the roller coaster moves because work is being done by various forms of energy on it.
00:00:18Now in a single trip around its track, it's going to go through several different forms of energy, some at the same time. Whether it's moving across the ground, as it is here, or whether it's hurtling down, as it's just about to there, it always has the same total amount of energy. And there's a relationship between the potential energy and the kinetic energy of the train that allows it to do its
00:00:45climbs and its dips, and its loops round and round. Now we're going to look at exactly what that relationship is between potential and kinetic energy.