Answer:
0.859375c
31.03 seconds
Explanation:
v' = Velocity of my ship = 0.4 c
u = Velocity of rocket = 0.7 c
c = Speed of light = 
s = Distance between my ship and enemy ship = 
Relativistic addition of speed is given by

The speed of the missile is 0.859375c
Time is given by

It will take 31.03 seconds to reach me.
Answer:
4.275v
<u><em>Thank you </em></u>