Chapter 9 Lesson 1 Spi’s:

Main Idea of Lesson 1: Understanding the difference between Potential and Kinetic Energy.

Potential = Stored energy Kinetic = Energy of a moving object

Vocabulary words: Take out your science journals… energy – ability to do work kinetic energy – energy of a moving object potential energy – energy that is stored in an object

Let’s read to find out the 5 Forms of Energy on PP. 326 and 327.

In your science journals, list the 5 forms of energy we just learned from reading PP. 326 and 327 (Go back and re-read PP. 326 and 327 if necessary.)

Let’s apply what you’re learning… What do you think happens to the chemical energy in a battery after the battery has been used for a long time? *Hint…think about your or your parents’ cell phone battery

Let’s apply what you’re learning… The energy changes to another form of energy, so the battery no longer works. No battery can hold infinite energy.

Let’s try another one… If you are holding an ice cube, what can you infer about the thermal energy of your hand?

You already know that ice melts when thermal energy transfers to it from warm air. You may also know an ice cube melts faster in your hand than it does in a glass. So, thermal energy MUST be transferred to the cube from your hand.

What is the main idea of Lesson 1?

Potential and Kinetic Energy Let’s find out more Potential and Kinetic Energy Let’s find out more.. Who’d like to begin reading aloud on P. 328?

What kind of energy does a stretched rubber band have?

Potential energy!!!

Why does a wind-up toy stop running after a while?

When a toy is wound up, it stores potential energy When a toy is wound up, it stores potential energy. When the toy runs, it changes to kinetic energy, which makes the toy move. When all of the stored potential energy has been converted to kinetic energy, the toy stops running.

Take a look at the chart on P Take a look at the chart on P. 329 Let’s copy this chart in your science journals.

What’s the main idea of this lesson?

Understanding the difference between Potential and Kinetic Energy!!!

Calculating Mechanical Energy P. 330 I need a volunteer to read, please.

How does the mechanical energy of a leaf change: 1 How does the mechanical energy of a leaf change: 1. before the leaf falls to the ground? 2. during its fall to the ground? 3. as the leaf hits the ground?

How does the mechanical energy of a leaf change: 1 How does the mechanical energy of a leaf change: 1. before the leaf falls to the ground? 2. during its fall to the ground? 3. as the leaf hits the ground? THE MECHANICAL ENERGY STAYS THE SAME DURING ALL 3 PHASES!!

When is the potential energy and the kinetic energy of a falling object the same value?

When is the potential energy and the kinetic energy of a falling object the same value? HALF WAY THROUGH THE FALL!!

What have we learned so far… What’s the difference between potential energy and kinetic energy?

What have we learned so far… Potential energy is stored energy; kinetic energy is the energy of a moving object.

What have we learned so far… Explain how potential energy and kinetic energy relate to mechanical energy.

What have we learned so far… An object’s mechanical energy includes both its kinetic energy and its potential energy.

What have we learned so far… When are an object’s potential energy and kinetic energy equal?

What have we learned so far… As the kinetic energy increases, potential energy decreases, and the two are only equal at the EXACT moment that half of the potential energy has been converted to kinetic energy.

What have we learned so far… How do you think an object’s speed affects its kinetic energy? Do you think mass affects kinetic energy? How might you test your answer?

What have we learned so far… As an object’s speed increases, its kinetic energy increases. If two objects are moving at the same speed, the more massive one (the heavier one) will have greater kinetic energy.

Way To Go… Now You Know The Difference Between Potential and Kinetic Energy!!!