A boat of anchor is rocked by waves of velocity 25  ms−1, having crests 100 m apart. They reach the boat once ever

To answer the question, we need to calculate the time it takes for the waves to reach the boat.

First, we can use the formula for wave velocity:

velocity = wavelength × frequency

Given that the velocity of the waves is 25 m/s and the crests are 100 m apart, we can rearrange the formula to solve for frequency:

frequency = velocity / wavelength

Substituting the given values, we have:

frequency = 25 m/s / 100 m

Simplifying, we find that the frequency of the waves is 0.25 Hz.

Now, to find the time it takes for the waves to reach the boat, we can use the formula:

time = 1 / frequency

Substituting the frequency we calculated, we have:

time = 1 / 0.25 Hz

Calculating, we find that the waves reach the boat once every 4 seconds.