Answer:v=3.08 m/s
Explanation:
Given
mass of student 
distance moved 
Force applied 
acceleration of system during application of force is a

using 
where v=final velocity
u=initial velocity
a=acceleration
s=displacement



I believe it is D. Earth spinning on it's axis.
The harmonic frequency of a musical instrument is the minimum frequency at which a string that is fixed at both ends in the instrument may vibrate. The harmonic frequency is known as the first harmonic. Each subsequent harmonic has a frequency equal to:
n*f, where n is the number of the harmonic and f is the harmonic frequency. Therefore, the harmonic frequency may be calculated using:
f = 100 / 2
f = 50 Hz