Question

An observer sits in a boat watching wave fronts move past the boat. The distance between successive wave crests is 0.80 m, and they are moving at 2.2 m / s.
What is the wavelength of these waves?
a. 1.6 m
b. 2.2 m
c. 0.80 m

What is the frequency of these waves?
a. 0.36 Hz
b. 2.8 Hz
c. 0.80 Hz

What is the period of these waves?
a. 0.80 s
b. 0.36 s
c. 2.8 s

Answer 1

To solve this problem we will use the three requested concepts: Wavelength, frequency and period.

The wavelength is the distance between each crest, therefore it is already given and is 0.8m

The correct answer is C.

The frequency can be described as a relationship between wave speed and wavelength therefore

$f = \frac{v}{\lambda}$

$f = \frac{2.2}{0.8}$

$f = 2.75Hz \approx 2.8Hz$

The correct answer is B.

The period is the inverse of the frequency therefore

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

$T = \frac{1}{2.8}$

$T = 0.35s$

The correct answer is B.