Ineed with this question what is the difference between speed and velocity? a) velocity describes speed with direction. b) there is no difference. c) velocity describes direction with position. d) velocity is used in space; speed is used on earth.

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?