Year 9 Science · Unit 3 · Lesson 5
Foundation Worksheet
Learning Goals
Fill the gap
Choose the correct word from the word bank. Each word is used once. Two words will not be used.
A ball rolling down a hill has energy because it is moving. The higher the ball starts, the more potential energy it has stored. When you stretch a rubber band, you store potential energy in it. The energy stored in the nucleus of a uranium atom is energy. The warmth of a hot cup of tea comes from its energy, the energy of its moving particles. Food, batteries and fossil fuels all store energy in the bonds between atoms. A lightning bolt carries energy as charges move between the clouds and the ground. The Sun gives out energy as electromagnetic waves that we can see.
1. Explain why chemical energy and electrical energy are both called forms of energy, even though they seem very different.
Odd one out
Circle the item that does not belong in each group. Then explain why it does not fit.
| # | Group | Odd one out, and why |
|---|---|---|
| 1 | Running athlete · Compressed spring · Wind turbine blade · Flowing river water | |
| 2 | Sunlight · Food · Fossil fuel · Battery | |
| 3 | Uranium nucleus · Nuclear fission · Burning coal · Radioactive decay |
2. A boomerang spins as it flies through the air. Name two forms of energy the boomerang has while it is in flight, and give a reason for each.
3. A 50 kg student stands on a diving platform 2 m above the water. Use GPE = mgh, with g = 10 m/s², to calculate the student’s gravitational potential energy.
GPE J
Data: speeds at the athletics carnival
A class timed a student and a netball over the same 20 m stretch of track. Speed = distance ÷ time. The jogging row is done for you.
| Object | Mass (kg) | Time for 20 m (s) | Speed (m/s) | Kinetic energy (J) |
|---|---|---|---|---|
| Student jogging | 50 | 10.0 | 2 | 100 |
| Student sprinting | 50 | 4.0 | ||
| Netball rolled along the track | 0.4 | 4.0 |
Source: sample class results.
4. Complete Table 1. Use KE = ½mv², and square the speed first.
5. The sprinting student and the netball move at the same speed. How many times more kinetic energy does the student have? Explain why.
The student has times as much
6. A child bounces on a trampoline. Describe the energy changes from the top of one bounce, down onto the mat, and back up again. Name at least four forms of energy, in the order they appear.