Question

A girl stands on a boat and feels the boat rise and fall 7 times in 1 minute. What is the period of the water wave? Give your answer to 3 significant figures.

Answer 1

A girl stands on a boat and feels the boat rise and fall 7 times in 1 minute.

First, let's find out the frequency of wave.

• In 1 minute (60 sec) , the boat shows two-fro motion for 7 times.

• So, in 1 sec, number of such motions = 7/60

Hence, frequency = 7/60 Hz.

Now, time period is reciprocal of frequency.

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

$\implies T = \dfrac{1}{( \frac{7}{60}) }$

$\implies T = \dfrac{60}{7 }$

$\implies T = 8.57$

So, time period of wave is 8.57 sec.