QUESTION 4 Your friend tosses a ball straight up with a velocity of 10m/s. At the top of the toss, the magnitude of the ball's velocity is vm/s and the magnitude of its acceleration is
m/s?

Suppose that 27 j of work is needed to stretch a spring from its natural length of 6 m to a length of 9 m. (a) how much work is needed to stretch the spring from 12 m to 14 m? j (b) how far beyond its natural length will a force of 78 n keep the spring stretched?