Wave period and wave speed
The time period of a wave can be calculated using the equation:
\(Time~period = \frac{1}{frequency}\)
\(T = \frac{1}{f}\)
This is when:
- the period (T) is measured in seconds (s)
- frequency (f) is measured in hertz (Hz)
Example
Calculate the time period of a wave with a frequency of 50 Hz.
\(T = \frac{1}{f}\)
\(T = 1 \div 50\)
\(T = 0.02~s\)
Question
Calculate the time period of a wave with a frequency of 400 Hz.
\(T = 1 \div 400\)
\(T = 0.0025~s\)
Calculating wave speed
The speed of a wave can be calculated using the equation:
wave speed = frequency Ă— wavelength
\(v = f~\lambda\)
This is when:
- wave speed (v) is measured in metres per second (m/s)
- frequency (f) is measured in Hertz (Hz)
- wavelength (λ) is measured in metres (m)
Example
What is the speed of a wave that has a frequency of 50 Hz and a wavelength of 6 m?
\(v = f \lambda\)
\(v = 50 \times 6\)
\(v = 300~m/s\)
Question
What is the speed of a wave with a frequency of 0.2 Hz and a wavelength of 25 m?
\(v = f \lambda\)
\(v = 0.2 \times 25\)
\(v = 5~m/s\)