Complete Question
The complete question is is shown on the first uploaded
Answer:
The elastic potential energy at point B is
The kinetic energy at point D is 
Explanation:
Looking at the given point we can observe that mechanically energy(i.e potential and kinetic energy ) is conserved and it value is 
So at point B


KE at point B is 50J
So 
Now at point D

at point D is 25J
So 
Answer:
275 MPa, -175 MPa
-0.63636
450 MPa
Explanation:
= Maximum stress
= Minimum stress
= Mean stress = 50 MPa
= Stress amplitude = 225 MPa
Mean stress is given by

Stress amplitude is given by


Maximum stress level is 275 MPa
Minimum stress level is -175 MPa
Stress ratio is given by

The stress ratio is -0.63636
Stress range is given by

Magnitude of the stress range is 450 MPa
The radiations detected by Arno Penzias and Robert Wilson
were the original heat from the Big Bang.
Today, we call those waves the "Cosmic Microwave Background".
I'm not sure, but I think those guys were awarded a Nobel Prize in Physics
for that discovery.
D). located out side the nucleus