Tommy is pushing on a box and is trying to move it. he pushes with 30 n of force and it still will not move. the box is pushing on tommy with n of force. a) 30 n b) 60 n c) 90 n d) it depends on the size of the box

A1-lb collar is attached to a spring and slides without friction along a circular rod in a vertical plane. the spring has an undeformed length of 5 in. and a constant k =25 lb/ft. knowing that the collar is released from being held at a determine, the speed of the collar and the normal force between the collar and the rod as the collar passes through b.