A spaceship traveling at 0.90c toward the earth fires a missile in the direction it is traveling. If the missile has a velocity of 0.40c relative to the spaceship, then calculate the velocity of the missile relative to someone who is on earth.

Two identical spaceships are under construction. The constructed length of each spaceship is 1.1 km. After being launched, spaceship A moves away from earth at a constant velocity (speed is 0.850c) with respect to the earth. Spaceship B follows in the same direction at a different constant velocity (speed is 0.6c) with respect to the earth. Determine the length that a passenger on one spaceship measures for the other spaceship.

Suppose a cosmic ray colliding with a nucleus in the Earth's upper atmosphere produces a muon that has a velocity v= 0.980c. The muon then travels at constant velocity and lives 1.52 us as measured in the muon's frame of reference. (You can imagine this as the muon's internal clock. See the figure below. Enter your answers to at least four significant figures. Assume the speed of light is 2.998 x 108 m/s.) اد us At (a) How long (in us) would the muon have lived as observed on the Earth if its velocity was 0.0690c? (b) How far (in m) would it have traveled as observed on the Earth? (c) What distance (in m) is this in the muon's frame?

Two spaceships are moving along the line connecting them. One of the spaceships shoots a missile towards the other. The missile leaves the attacking spaceship at 0.955c and approaches the other at 0.755c.   What is the relative velocity of the two spaceships? Express it as a ratio to the speed of light. Let the relative velocity of the spaceships be positive if they are approaching each other and negative if they are moving apart from one another.