Year 9 Science · Unit 3 · Lesson 1

Introduction to Energy

Foundation Worksheet

Name

Date

Class

Learning Goals

Match each form of energy to a real example.
Tell an energy transfer from an energy transformation.
Use measurements in kilojoules to compare the energy devices use.

Warm Up

Fill the gap

Choose the correct word from the word bank. Each word is used once. Two words will not be used.

transfer force energy kinetic conservation joule power transformation potential

The capacity to do work or cause change is called . It is measured in the SI unit called the (J). Energy due to motion is called energy, while energy stored because of an object’s position or condition is called energy. When energy moves from one place to another without changing form, it is an energy . When energy changes from one form into a different form, it is an energy . The idea that energy can never be created or destroyed is called the law of of energy.

Match each form of energy to an example

Write the letter of the matching example in the middle column. Each letter is used once.

Form of energy	Letter	Example
Kinetic energy		A. Water held behind a dam in the Snowy Mountains
Gravitational potential energy		B. An outback road surface heated to 70 °C in summer
Elastic potential energy		C. A didgeridoo being played
Thermal energy		D. Coal stored in the Latrobe Valley, Victoria
Chemical energy		E. A stretched rubber band before it is let go
Electrical energy		F. Sunlight falling on Bondi Beach
Light energy		G. An AFL player sprinting across the MCG
Sound energy		H. Lightning during a Darwin storm

1. A toaster changes electrical energy into thermal energy to brown bread. Is this an energy transfer or an energy transformation? Explain how you know.

Recall 2 marks

Your Turn

Sort it: transfer or transformation?

Write each example in the correct box. Ask yourself: does the energy change form, or only move to a new place?

A hot pie warms your hands A solar panel turns sunlight into electricity A car’s brake discs get hot as the car slows down Electricity travels along power lines to a school A cyclist’s leg muscles turn the pedals Heat moves from a camp fire to a billy can The sound of the school bell reaches your ears A torch battery makes the bulb glow

Energy transfer

Energy transformation

2. An AFL player kicks a football. Name TWO forms of energy involved in the kick, and say where in the kick each one is found.

Apply 2 marks

Go Deeper

Scenario: an energy meter at home

Mia plugged three devices, one at a time, into a plug-in energy meter. Each device ran for exactly 1 minute. The meter showed how much electrical energy went into each device.

Table 1. Electrical energy used in 1 minute

Device	Electrical energy in 1 minute (kJ)	Main useful form of energy out
Toaster	48
Hair dryer	90
Desk fan	3

Source: sample class results.

3. Complete the last column of Table 1. Then calculate how many times more electrical energy the toaster used than the desk fan in the same minute.

Apply 4 marks

The toaster used times as much

4. After an hour, the desk fan’s motor feels warm. Mia says: “Some of the fan’s energy has been used up.” Explain what really happened to that energy.

Analyse 2 marks

Show What You Know

Scenario: a school sausage sizzle

A gas barbecue cooks sausages. Its flame glows blue and the sausages sizzle on the hot plate. A portable speaker plays music, and a Year 7 student rolls past on a scooter.

5. Describe the energy in this scene. Name at least four different forms of energy and the object that has each one. Give one energy transfer and one energy transformation, and say where the energy from the gas ends up.

Apply 5 marks