Answer:
The answers to the questions have been solved in the attachment.
Explanation:
The answers to part a to e are all contained in the attachment. For answer part b, temperature and frequency were assumed to be fixed or constant. V² is directly proportional to T telling us that variation in T gives us a square in the frequency variation. This tells us why it is difficult when both frequencies are on this side of the black body.
Answer:

Explanation:
The density changes means that the length in the direction of the motion is changed.
Therefore,

Given :
Side, b = h = 0.13 m
Mass, m = 3.3 kg
Density = 8100 
So,


l = 0.024 m
Then for relativistic length contraction,







Therefore, the speed of the observer relative to the cube is 0.9833 c (in the units of c).
C.There is an invisible magnetic field around the magnet where it exerts magnetic force
Energy can change forms and be transferred.