Two spaceships approach Earth from opposite directions.One has a speed of 0.21c and the other a speed of 0.34c,both relative to Earth.What is the speed of one spaceship relative to the other?
A)0.51c
B)0.55c
C)0.58c
D)0.61c
E)0.64c

Question

Quizplus · Accepted Answer

The correct answer is A because the relative speed of the two spaceships is given by the formula:v = (v1 + v2) / (1 + v1 * v2 / c^2)where v1 and v2 are the speeds of the two spaceships relative to Earth, and c is the speed of light. Plugging in the given values, we get:v = (0.21c + 0.34c) / (1 + 0.21c * 0.34c / c^2) = 0.51c

Two Spaceships Approach Earth from Opposite Directions