Wavelength

Key Stage 3

Wavelength is the distance between a point on one wave and an identical point on the next wave.


The wavelength is the length of one wave including the peak and trough.

Wavelength is the distance between two identical points on adjacent waves.

Wavelength is a scalar quantity because it has magnitude only.


The wavelength is the length of one wave including the peak and trough.

NB: You should remember this equation with v as the subject of the formula. Wavelength = (Wave Speed)/(Frequency)

\(\lambda = \frac{v}{f}\)

Where

\(\lambda\) = The wavelength of the wave.

\(v\) = The wave speed of the wave.

\(f\) = The frequency of the wave.

A wave with frequency 700Hz travels at a speed of 340m/s. Calculate the wavelength of the wave correct to two significant figures.

A 630MHz radiowave travels at 300,000,000m/s in a vacuum. Calculate the wavelength of this radiowave correct to two significant figures.

1. State the known quantities

f = 700Hz

v = 340m/s

1. State the known quantities

f = 630MHz = 630x10⁶Hz

v = 300,000,000m/s = 3x10⁸m/s

2. Substitute the numbers into the equation and solve.

\( \lambda = \frac{v}{f}\)

\( \lambda = \frac{340}{700}\)

\( \lambda = 0.48571m\)

\( \lambda \approx 0.48m\)

2. Substitute the numbers into the equation and solve.

\( \lambda = \frac{v}{f}\)

\( \lambda = \frac{630 \times 10^6}{3 \times 10^8}\)

\( \lambda = 2.1m\)