3. Twelve waves pass a dock in 3.60 If the waves are traveling at 19.5 m/s , what is the wavelength of the waves?

65m

Explanation:

Twelve waves pass a dock in 3.60 If the waves are traveling at 19.5 m/s , what is the wavelength of the waves?

Velocity of a wave is expressed as;

V = frequency × wavelength

Given

Velocity = 19.5m/s

Frequency is the number of oscillations completed in 1sec, hence

Frequency= 3.6/12

Frequency = 0.3

Wavelength = vel/freq

Wavelength = 19.5/0.3

Wavelength = 65m

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.