Question

which equation should be used to calculate the speed of a wave?
speed = frequency x wavelength
speed = frequency x hertz
speed = period x wavelength
speed = period x hertz

Explanation:

The formula for wave speed \(v\) is \(v = f\lambda\), where \(f\) is the frequency and \(\lambda\) is the wavelength. Hertz is the unit of frequency. The period \(T\) is related to frequency by \(f=\frac{1}{T}\), so \(v=\frac{\lambda}{T}\), not \(v = T\times\lambda\) or \(v=T\times f\) (since \(T\times f = 1\) when substituting \(f=\frac{1}{T}\)).

Answer:

speed = frequency x wavelength