Answer:
2.5 m/s
Explanation:
The speed of a wave is given by:
[tex]v=f\lambda[/tex]
where
f is the frequency
[tex]\lambda[/tex] is the wavelength
The wave in this problem hits the beach about every 2.0 seconds: this means that its period is 2.0 s. So the frequency is the reciprocal of the period
[tex]f=\frac{1}{2.0 s}=0.5 Hz[/tex]
The crests are 5.0 m away from each other, so the wavelength is
[tex]\lambda=5.0 m[/tex]
Therefore, the speed of the wave is
[tex]v=(0.5 Hz)(5.0 m)=2.5 m/s[/tex]
