i really cant figure this out

Question

A space probe is being prepared for a deep-space mission. The engineers have divided the trip into five segments based on the required changes in motion, as noted in the table. During which parts of the trip must the engineers apply the principles of general relativity? (Note that the velocities are listed as a percentage of the speed of light, c. The direction is positive when moving away from Earth and negative when moving toward Earth.)

Planned Space Probe Mission

Trip segment Initial velocity (% c) Final velocity (% c)

A                          0                        +90

B                        +90                      +90

C                        +90                       -90

D                        -90                        -90

E                         -90                           0

A. Apply general relativity to segment B

B. Apply general relativity to segment C

C. Apply general relativity to segment A

D. Apply general relativity to segment E

Answer 1

I don't know all the mathematics of general relativity, But for this problem you need to know the difference between special relativity and general relativity. The planning of the space mission is done by engineers in the initial frame of reference. When the ship is accelerating or decelerating, it is not in an inertial reference frame because the speed is not constant. When the space ship is travelling a 90% of the speed of light and ends at 90% of the speed of light. Its speed is constant and therfore its in an inertial reference frame (Newton's First Law) with respect to the initial reference frame of the Engineers. Special relativity is "Special" because it only covers inertial reference frames. General Relativity must be used if there is acceleration or deceleration.

A Is there constant velocity? No. Apply general relativity

B is there constant velocity? Yes Do not need to apply general relativity.

C Is there constant velocity? ________________________________________

D Is there constant velocity? _________________________________________