Answer:
ramp b requires less force than ramp a
Explanation:
Yes, <span> the moon fall partly into earth's shadow when it is in its full size</span>
I think it’s D) all of the above
(a) 
<u>Explanation:</u>
Given:
Moment of Inertia of m₁ about the axis, I₁ = m₁x²
Moment of Inertia of m₂ about the axis. I₂ = m₂ (L - x)²
Kinetic energy is rotational.
Total kinetic energy is 
Work done is change in kinetic energy.
To minimize E, differentiate wrt x and equate to zero.

Alternatively, work done is minimum when the axis passes through the center of mass.
Center of mass is at 