Year 9 Science · Unit 4 · Lesson 3
Foundation Worksheet
Learning Goals
Match each term to its definition
Draw a line connecting each term on the left to its correct definition on the right. Or write the matching letter next to each term.
| Term | Your answer | Definition and unit |
|---|---|---|
| Amplitude | A. How fast the wave travels through a medium. Unit: metres per second (m/s). | |
| Wavelength | B. The number of complete waves passing a point per second. Unit: hertz (Hz). | |
| Frequency | C. The maximum displacement of a particle from its equilibrium position. Unit: metres (m). | |
| Wave speed | D. The distance between two identical adjacent points on a wave (e.g. crest to crest). Unit: metres (m). | |
| Hertz | E. The unit of frequency; equal to one complete cycle per second. |
True or False? Fix the false ones
Circle T or F for each statement. If the statement is false, rewrite it correctly on the line below.
Amplitude is measured from the crest to the trough of a wave.
Correct it:
If two waves travel at the same speed and one has a higher frequency, it must have a shorter wavelength.
Correct it:
A tsunami is more destructive than a normal ocean wave because it has a much higher frequency.
Correct it:
Period and frequency are inversely related — doubling the frequency halves the period.
Correct it:
1. A sound wave in air has a frequency of 170 Hz. The speed of sound in air is 340 m/s. Calculate the wavelength of this sound wave. Show your working using λ = v ÷ f.
2. Two ocean waves have the same frequency. Wave A has an amplitude of 0.5 m and Wave B has an amplitude of 1.0 m. Which wave carries more energy, and by how much? Use the relationship: energy ∝ amplitude².
Wrap Up
In one sentence, what was the main idea of this lesson?