Q 56

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

Q 57

Two spaceships,each 100 m long in its own rest frame,approach Earth from opposite directions,each with a speed 0.50c relative to Earth.As measured by a passenger in one of the spaceships,how long is the other spaceship?
A)50 m
B)60 m
C)70 m
D)80 m
E)90 m

Q 58

Two spaceships,each 100 m long in its own rest frame,approach Earth from opposite directions,with equal speeds relative to Earth.As measured by a passenger in one of the spaceships,the other spaceship is 96 m long.What is the speed of the spaceships relative to Earth?
A)c/7
B)c/6
C)c/5
D)c/4
E)c/3