Answer: 529.9 Hz
Explanation:
Here we need to use the Doppler equation, so we have:
f' = f*(v + v0)/(v - vs)
Here, f is the frequency = 500Hz
v is the velocity of the wave, = 334m/s
v0 is the velocity of the observer = 20m/s
vs is the velocity of the source = 0m/s
Then we have:
f' = 500Hz*(334m/s + 20m/s)/(334m/s) = 529.9 Hz
The correct formula to use for the situation given above is: F = MA, where F is the applied force, M is the mass of the object and A is the acceleration.
From the details given in the question, we are told that:
F = 18, 400N
M = 145 g = 145 / 1000 = 0.145 kg
A = ?
From the equation F = MA
A = F / M
A = 18,400 / 0.145 = 126,896.55 = 1.27 *10^5.
Therefore, the correct option is C.