Transforming and Conserving Energy: Page 65

QUESTION: What happens to energy once it is used up?

OBJECTIVE: SWBAT give examples of energy being transformed and conserved.

VOCABULARY: Law of conservation of energy energy transformation

Transforming and Conserving Energy:

Write these questions onto page 65

1. List the energy transformations that take place at Niagara Falls.

2. List the energy transformations that take place while skiing.

3. List all the energy transformations that take place from the time a lettuce plant makes lettuce leaves until the person who ate the lettuce runs a race.

EnergyYou’ve already learned that energy is the ability to do work and that there are many forms of energy

MechanicalHeatChemicalRadiantElectricalSoundNuclear

What Happens to Energy When it is Used up?

Energy is never used up.

Just like matter, energy cannot be created or destroyed. This is called the Law of conservation of energy.

How is Energy Transformed(Changed)?

Let’s look at some examples of energy transformation.

How is Energy Transformed As Wood Burns?

The wood begins with potential chemical energy.

As the wood burns this potential chemical energy is transformed into both heat and light energy.

How is Energy Transformed During Lightning?

The lightning begins as electrical energy.

When the lightning bolt forms the electrical energy is transformed into both heat, light and sound(thunder) energy.

How is Energy Transformed When a Person Jumps?

This example starts with the jumper getting his energy from food.

The food starts out as chemical energy. The muscles change this to mechanical energy. Some energy is also changed to heat energy to warm the body and because of friction between the jumper and the track and air.

Why Don’t the Metal Balls Move Forever?During any energy transformation that takes place on Earth some energy is changed into heat due to friction and air resistance.

So no machine will go on forever.

Can You Explain These Transformations?Watch the two videos and in your notebook list the energy transformations shown.

Transforming and Conserving Energy: page 65

Check that the answers to these questions are in your notes.

1. List the energy transformations that take place at Niagara Falls.

2. List the energy transformations that take place while skiing.

3. List all the energy transformations that take place from the time a lettuce plant makes lettuce leaves until the person who ate the lettuce runs a race.

VOCABULARY

Law of conservation of energy-the rule that energy cannot be created or destroyed, just changed from one form into another.

Energy transformation-changing energy from one type into another.