Aspaceship is moving in a straight line away from earth at 0.80c, measured relative to earth. it launches a missile that moves away from the spaceship in the forward direction at 0.60c, relative to the ship. relative to earth, what is the speed of this missile?

a. c
b. greater than c but less than 1.4c
c. 1.4 c
d. greater than 0.80c but less than c

Suppose a force of 60 n is required to stretch and hold a spring 0.1 m from its equilibrium position. a. assuming the spring obeys hooke's law, find the spring constant k. b. how much work is required to compress the spring 0.5 m from its equilibrium position? c. how much work is required to stretch the spring 0.6 m from its equilibrium position? d. how much additional work is required to stretch the spring 0.1 m if it has already been stretched 0.1 m from its equilibrium? a. kequals 600