The Wave Equation

define wave speed

The distance travelled by a wave each second

what is the symbol of wave speed and what is it measured in?

Wave speed is given the symbol ν and is measured in metres per second (m/s)

what is wave speed?

Wave speed is the speed at which energy is transferred through a medium

true or false: Transverse and longitudinal waves both obey the wave equation

true

what is the wave equation?

wave speed = frequency x wavelength

what are the symbols for the wave speed = frequency x wavelength equation

• v = wave speed in metres per second (m/s)

• f = frequency in Hertz (Hz)

• λ = wavelength in metres (m)

A wave in a pond has a speed of 0.15 m/s and a time period of 2 seconds. Calculate: a) The frequency of the wave

Step 1: List the known quantities

• Time period, T = 2 s

Step 2: Write out the equation relating time period and frequency

Step 3: Rearrange for frequency, f, and calculate the answer

f = 1 ÷ T = 1 ÷ 2

Frequency, f = 0.5 Hz

A wave in a pond has a speed of 0.15 m/s and a time period of 2 seconds. Calculate: b) The wavelength of the wave

Step 1: List the known quantities

• Wave speed, v = 0.15 m/s

• Frequency, f = 0.5 Hz

Step 2: Write out the wave speed equation

v = f × λ

Step 3: Rearrange the equation to calculate the wavelength

λ = v ÷ f

Step 4: Use the frequency you calculated in part (a) and put the values into the equation

λ = 0.15 ÷ 0.5

Wavelength, λ = 0.30 m