Spaceships A and B move in opposite directions at the same speed of  0.863c  relative to earth, with A moving away from earth and B moving toward earth. Find the velocity of B relative to A.

A spaceship moves past Earth with a speed of 0.908c. As it is passing, a person on Earth measures the spaceship's length to be 74.2 m.   (a) Determine the spaceship's proper length (in m).  m (b) Determine the time (in s) required for the spaceship to pass a point on Earth as measured by a person on Earth.  s (c) Determine the time (in s) required for the spaceship to pass a point on Earth as measured by an astronaut onboard the spaceship.  s

An L = 47.0 ncm wire is moving to the right at a speed of v = 6.50 m/s across two parallel wire rails that are connected on the left side, as shown in the figure. The whole apparatus is immersed in a uniform magnetic field that has a magnitude of B = 0.910 T and is directed into the screen. What is the emf induced in the wire? If the moving wire and the rails have a combined total resistance of 1.15 Ohms, what applied force would be required to keep the wire moving at the given velocity? Assume that there is no friction between the moving wire and the rails.

Two rocket ships approach Earth from opposite directions, each with a speed of 0.85c relative to Earth. What is the speed of one ship relative to the other?