Answer:
0.408 c.
Explanation:
given,
Cruiser travelling speed, v = 0.6 c
Pursuit ship speed,u = 0.81 c
speed of the he cruiser relative to the pursuit ship =?
now,
[tex]v' = \dfrac{v-u}{1-\dfrac{vu}{c^2}}[/tex]
c is the speed of light
[tex]v' = \dfrac{0.6c-0.81c}{1-\dfrac{0.6c \times 0.81c}{c^2}}[/tex]
[tex]v' = \dfrac{-0.21c}{1-0.486}[/tex]
[tex]v' = -0.408 c[/tex]
Speed of the cruiser relative to pursuit ship is equal to 0.408 c.