Question

A wave of period T=10ms is propagated at a velocity v=250m/s. The wavelength is ?

Answer 1

Explanations & Calculations

• All the parameters described with respect to a wave: wavelength, period & speed are related according to the equation $\small v=f\lambda$ where $\small v$ is for the speed, $\small \lambda$ is for the wavelength & $\small f$ is fo the frequency of the wave.
• Frequency is the reciprocal of the period & that you may know by now. $\small f= \large\frac{1}{T}$.
• Then the above equation could be re-written as follows & plugging the given data correspondingly & subjecting the term, yields the result that is needed.
• Then,

$\qquad\qquad \begin{aligned} \small v&=\small f\lambda\\ &=\small \frac{1}{T}.\,\lambda\\ \small \lambda &=\small v\times T\\ &=\small 250\,ms^{-1}\times0.01\,s\\ &=\small \bold{2.5\,m} \end{aligned}$

• Note that all the units of each term should be compatible. $(\small ms\to s)$