What is the relative speed between two objects approaching each other if each is travelling at speed of 0.6 c as measured by an observer on Earth?
A)0.72 c
B)0.66 c
C)0.88 c
D)1.2 c

Question

Quizplus · Accepted Answer

The relative speed $v$ between two objects moving towards each other at speeds $u$ and $v'$ (both relative to an observer, and in this case $u = v' = 0.6c$) in the context of special relativity is given by the formula: $$v = \frac{u + v'}{1 + \frac{uv'}{c^2}}$$ Substituting $u = 0.6c$ and $v' = 0.6c$, we get: $$v = \frac{0.6c + 0.6c}{1 + \frac{(0.6c)(0.6c)}{c^2}} = \frac{1.2c}{1 + 0.36} = \frac{1.2c}{1.36} = 0.8824c$$ Thus, the relative speed is approximately $0.88c$, which corresponds to choice C.

What Is the Relative Speed Between Two Objects Approaching Each