Doppler Effect is required to solve the problem. The Doppler effect is the change in the perceived frequency of any wave movement when the emitter, or focus of waves, and the receiver, or observer, move relative to each other. The general formula of observed frequency, due to Doppler's effect is as follows,
= Frequency observed by observer
v = Velocity of Sound
= Velocity of observer
= Velocity of source
= Frequency of source
PART A) Replacing our values we have that,
PART B) Here the same procedure is performed but this time repeated in the opposite direction.
We first calculate the acceleration on the ball using:
2as = v² - u²; u = 0 because ball is initially at rest
a = (36)²/(2 x 0.35)
a = 1850 m/s²
F = ma
F = 0.058 x 1850
= 107.3 Newtons
They travel at different speeds
The correct answer is b).
The second one because it has a longer way that the rotation has to go around. the first one will just be quicker. it depends how the question wants you to describe kinetic energy! if it wants quicker, then 1. if longer movement, then 2!
