Answer:
Since the spring mass system will execute simple harmonic motion the position as a function of time can be written as
'A' is the amplitude = 6 inches (given)
is the natural frequency of the system
At equilibrium we have

Applying values we get

thus natural frequency equals

Thus the equation of motion becomes

At time t=0 since mass is at it's maximum position thus we have

Thus the position of mass at the given times is as follows
1) at

2) at

3) at

4) at

5) at

Neglecting air resistance, the horizontal component remains constant. The angle doesn't matter.
Answer:
F= 2666.66 N
N=334.22 RPM
Explanation:
Given that
Diameter of pulley ,d= 0.15 m
Radius ,r= 0.075 m
Torque ,T= 200 N.m
Power ,P = 7 kW
Lets take force = F
T = F .r

Now by putting the values

F= 2666.66 N
Lets take rotational speed = N RPM
We know that


Now by putting the values in the above equation

N=334.22 RPM