Let the vector position of the object in the (x-y) plane be

The applied force is

By definition, the applied torque is

Answer:
Potential energy is highest at the top of the loop, and kinetic energy is highest at the bottom of the loop.
Answer:
So the mass of the second object M will be 1.951 kg
Explanation:
We have given mass of the first object
and its velocity 
Mass of the second object
it is at rest so its velocity 
From conservation of momentum we know that
Initial momentum = final momentum
So 


M = 1.951 kg
All electromagnetic radiation ... all wavelengths, all frequencies ... has the
same speed, as long as you're measuring all through the same medium.
The speed is fastest in vacuum ... 299,792,458 meters per second. It's
slower than that in any material, and different in every material.