A. it can be modified or rejected
Answer:
The relative speed of 1 relative to 2 is 0.88c
Explanation:
In relativistic mechanics the relative speed between 2 objects moving in different direction is given by

Since it is given that

Applying values in the formula we get

Answer:
d = 20.25 m
Explanation:
h = 6m, V = 14 m/s, θ=14°
⇒ Vx=V × Cosθ=13.58 m/s and Vy = V × Sinθ=3.39 m/s
to find time t by h=-Vy t + 1/2 g t² (after putting value and simplifying) (-ve for downward motion)
4.9 t² - 3.39 t - 6 =0
⇒ t=1.5 sec (ignoring -ve root)
Now Vx = d/t
13.5 m/s = d / 1.5 s ⇒ d = 20.25 m