The first question's answer is :
If, F=ma
Then, 15N= 2.1kg (a)
15/2.1=a
7.14=a
Therefore, acceleration = 7.14m/s^2
sorry I am not sure about the second question :-(
It’s 21 c it all on the weather outside but most of the time it’s on 21
<span>On the scale the only external forces are the man's weight acting downwards and the normal force which the scale exerts back to support his weight.
So F = Ma = mg + Fs
The normal force Fs (which is actually the reading on the scale) = Ma + Mg
But a = 0
So Fs = Mg which is just his weight.
Fs = 75 * 9.8 = 735N</span>
Answer:
0.17547 m
Explanation:
m = Mass of block = 
v = Velocity of block = 10.8 m/s
k = Spring constant = 125 N/m
A = Amplitude
The kinetic energy of the system is conserved

The amplitude of the resulting simple harmonic motion is 0.17547 m