Question

A wave travels with a speed of 720cm/min and the distance between the two consecutive crests is 30mm. Calculate:
a. frequency
b. time period

please help

Answer 1

Answer:

frequency is 4Hz

time period is 0 . 25 sec

Explanation:

given lamda is 3cm

speed is 720cm/min =12cm/sec

so speed = lamda/T

12= 3/T

T = 1/4

f=4Hz

Answer 2

Frequency, f = 4 Hz

Time period, T = 0.25 s

Explanation:

Given that,

Speed of the wave, v = 720 cm/min = 0.12 m/s

The distance between the two consecutive crests is 30 mm, $\lambda=30\ mm=0.03\ m$

The relation between the speed, frequency and the wavelength is given by :

$v=f\times \lambda$

$f=\dfrac{v}{\lambda}$

$f=\dfrac{0.12\ m/s}{0.03\ m}$

f = 4 Hz

Let T is the time period of the wave. It can be calculated as :

$T=\dfrac{1}{f}$

$T=\dfrac{1}{4}$

T = 0.25 s

So, the frequency of the wave is 4 Hz and time period is 0.25 s. Hence, this is the required solution.