Question

The distance between three consecutive crests of wave is 60 cm. If the waves are produced at the rate of 180/ min, calculate:

1. wavelength
2. time period
3. wave velocity.

Answer 1

(i) We know distance between two consecutive creasts = λ

⇒ λ = ${\displaystyle \frac{60}{2}=30}$cm

(ii) Frequency = 180 min^-1 

f = ${\displaystyle \frac{180}{60}}$S^-1 

f = 3 s^-1 or 3 Hz

∴ Time period = T = ${\displaystyle \frac{1}{\text{f}}=\frac{1}{3}=0.33}$s

(iii) Wave velocity = v = ?

v = λf

v = 30 × 30

v = 90 cms^-1