wave speed = frequency × wavelength (v = f × λ)

The speed of a wave through a medium. Given by the wave equation: wave speed = frequency × wavelength (v = f × λ)

The number of waves produced each second. Frequency is measured in Hertz (Hz)

The distance between one wave crest (or trough) and the next is the wavelength of the wave.

A prefix is added to units to represent large or small values , for example 1 km = 1000 m and 1 mm = 0.001 m

Using the wave speed equations

Combined science

In the Electromagnetic waves unit, they will build on this knowledge to learn about the reflection and refraction of light, other types of electromagnetic radiation in the EM spectrum and the helpful and harmful effects of each type of radiation.

In the Waves unit, pupils learnt about the properties and propagation of transverse and longitudinal waves.

Measuring waves

Which of these can cause the speed of a wave to change?

A wave has a wavelength of 1.5 m and a frequency of 5.0 Hz. What is its speed? 

A wave in a rope has a wavelength of 0.3 m, and it travels with a wave speed of 1.5 m/s. Calculate the frequency of the wave.

A sound wave with a frequency of 150 Hz travels at 330 m/s in air. Calculate the wavelength of the wave.

Starting with the longest, put the waves in order of decreasing wavelength.

A wave has a wavelength of 60 mm and it travels with a wave speed of 3.0 km/s. Calculate the frequency of the wave.

What is the name for the number of vibrations a wave makes in a second?

Which of these units cannot be used as a measure of wavelength?

What is an equivalent frequency of 330 000 Hz?

If the frequency of each wave is the same, the wavelength will be the same.

The frequency of each wave is equal to the wavelength.

The transverse wave has a lower frequency than the longitudinal wave.

The transverse wave has a higher frequency than the longitudinal wave.

A transverse wave and a longitudinal wave have the same speed. Which statement about the waves is correct?

Put these prefixes in order starting with the smallest.

This lesson will soon be taken down.

Using the wave speed equations

Lesson outcome