your older twin born only 15.0 minutes before you, boards a spaceship and travels out among the stars at 2.436699 x 10^8 m/s. according to your watch they spend 60.0 minutes travelling at that speed. when they get back to earth they are no longer 15 minutes older than you. who is older than who and by how much

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