Question

In the middle of the Indian Ocean, the tsunami referred to in the passage was a train of pulses approximating a sinusoidal wave with speed 200 m/s and wavelength 150 km. What was the approximate period of these pulses?

A. 1 min
B. 3 min
C. 5 min
D. 15 min

Answer 1

13 min

Step-by-step explanation:

Period: This is the time taken by a wave to make one complete oscillation. The S.I unit of period is second (s).

The expression for period, speed and wavelength of a wave is given as,

v = λ/T................ Equation 1

Where v = speed of the wave, λ = wavelength of the wave, T = period of the wave.

making T the subject of the equation,

T = λ/V................ Equation 2

Given: λ = 150 km = 150000 m, v = 200 m/s.

Substitute into equation 2

T = 150000/200

T = 750 seconds.

T = 750/60 =

T = 12.5 min

T≈ 13 min

Thus the approximate period of the wave = 13 min