An observer from the beach see an anchored fishing boat rise and fall through a total range of 3.5 m once every 4 s as the waves whose crests are 25 m apart pass it. Find (a) the frequency of the waves, (b) the velocity of an individual water molecule at the surface.
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a) The period is 4 s. The relationship between period and frequency is
F = 1/T = ______ Hertz
b) The individual water molecule does the same up and down that the boat does. Velocity is given by
V = displacement / time = (3.5 m - 3.5 m) / 4 s = 0
Speed is not a vector, so if you want speed, you can say the total trip is 7 meters and the speed is given by
speed = length of trip / time = 7 m / 4 s = ____ m/s
F = 1/T = ______ Hertz
b) The individual water molecule does the same up and down that the boat does. Velocity is given by
V = displacement / time = (3.5 m - 3.5 m) / 4 s = 0
Speed is not a vector, so if you want speed, you can say the total trip is 7 meters and the speed is given by
speed = length of trip / time = 7 m / 4 s = ____ m/s