On the lake, in calm weather, a heavy anchor was dropped from the boat. Waves came from the place of the throw.

On the lake, in calm weather, a heavy anchor was dropped from the boat. Waves came from the place of the throw. A man standing on the shore noticed that the wave reached him after 50 s, the distance between adjacent wave crests was 50 cm, and in 50 s there were 20 bursts on the shore. How far from the shore was the boat?

t = 50 s.

λ = 50 cm = 0.5 m.

N = 20.

S -?

The distance from the place where the stone is thrown to the shore S will be determined by the formula: S = V * t, where V is the speed of wave propagation, t is the time the wave travels from the place where the stone is thrown to the shore.

We find the speed of the wave V by the formula: V = λ * ν, where λ is the wavelength, ν is the frequency of the wave.

According to the definition, the frequency ν is the number of oscillations per unit of time, it is determined by the formula: ν = N / t.

S = λ * ν * t = λ * N * t / t = λ * N.

S = 0.5 m * 20 = 10 m.

Answer: from the place of throwing the stone to the shore is S = 10 m.