Answer:
Long question good luck:)
Explanation:
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).
False because faster moving slope would be going up and slower would be going down because its decreasing
No not all, because not all electrical field attract and repel