Waves KS3 Activate Science - Free Printable

Let’s go step by step through each task on the worksheet.

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Task 1: Label the wave diagram using: peak, trough, frequency, amplitude, wavelength

We’re looking at a transverse wave (like a sine wave). Here’s how to label it:

- Peak: The highest point of the wave.
- Trough: The lowest point of the wave.
- Amplitude: The distance from the middle line (rest position) to the peak (or trough). It shows how “tall” the wave is.
- Wavelength: The distance between two peaks (or two troughs) — one full wave cycle.
- Frequency: This isn’t something you can draw directly on the diagram — it’s how many waves pass a point per second. But if you were labeling, you’d note that more waves in the same space = higher frequency.

So on the diagram:
- Point to the top of a hump → peak
- Point to the bottom of a dip → trough
- Draw an arrow from the center line to the peak → amplitude
- Draw an arrow from one peak to the next peak → wavelength
- Frequency would be noted as “how many waves fit in this space” — not drawn, but understood.

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Task 2: Match keyword to description and units

Left column: Amplitude, Wavelength, Frequency
Middle column: A, B, C descriptions
Right column: meters, meters, Hertz

Let’s match:

- Amplitude → C. The maximum distance between a particle’s resting position and a peak/trough → Unit: meters (it’s a distance)
- Wavelength → B. The distance of one whole wave (between 2 peaks/troughs) → Unit: meters (also a distance)
- Frequency → A. The number of waves passing a point each second → Unit: Hertz (Hz)

So:
- Amplitude → C → meters
- Wavelength → B → meters
- Frequency → A → Hertz

Now complete the sentences:

Words to use: before, echo, pressure, reflects, slower, superpose, vibrates

Sentence:
*A sound wave is created when something* vibrates.
*Sound waves travel as* pressure *waves in the air or other materials.*
*Sound waves travel much* slower *than light waves.*
*This is why lightning is seen* before *we hear thunder.*
*When a wave hits a barrier it* reflects *and travels the other way.*
*When a sound wave reflects off a surface, it creates an* echo.
*Two waves in the same place add together. We say they* superpose.

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Task 3:

1. Describe the features of a longitudinal wave? Include an example.

Longitudinal waves move back and forth in the same direction the wave travels. Think of a slinky being pushed and pulled — the coils bunch up and spread out. These bunched-up parts are called compressions, and the spread-out parts are rarefactions.

Example: Sound waves in air — air molecules vibrate back and forth along the direction the sound is moving.

2. Describe the features of a transverse wave? Include an example.

Transverse waves move up and down (or side to side) while the wave travels forward. The motion is perpendicular to the direction of the wave.

Example: Light waves, or waves on a string when you shake it up and down.

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Task 4:

1. Describe the difference between a compression and a rarefaction.

In a longitudinal wave (like sound):

- Compression = where particles are squeezed together (high pressure)
- Rarefaction = where particles are spread apart (low pressure)

They alternate as the wave moves.

2. Explain what is meant by superpose.

When two waves meet in the same place, they combine. If both are going up, they make a bigger wave. If one goes up and one goes down, they might cancel out. This combining is called superposition.

Simple example: Two people shaking a rope — their waves add together when they meet.

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Final Answer:

Task 1 Labels:
- Peak → top of wave
- Trough → bottom of wave
- Amplitude → height from center to peak
- Wavelength → distance from peak to next peak
- Frequency → how many waves pass per second (not drawn, but implied by spacing)

Task 2 Matches:
- Amplitude → C → meters
- Wavelength → B → meters
- Frequency → A → Hertz

Completed sentences:
A sound wave is created when something vibrates. Sound waves travel as pressure waves in the air or other materials. Sound waves travel much slower than light waves. This is why lightning is seen before we hear thunder. When a wave hits a barrier it reflects and travels the other way. When a sound wave reflects off a surface, it creates an echo. Two waves in the same place add together. We say they superpose.

Task 3 Answers:
1. Longitudinal wave: particles move parallel to wave direction; has compressions and rarefactions. Example: sound waves.
2. Transverse wave: particles move perpendicular to wave direction. Example: light waves or shaking a rope.

Task 4 Answers:
1. Compression = high pressure (particles close); Rarefaction = low pressure (particles spread).
2. Superpose = when two waves meet and combine their effects.