a person standing on the edge of a seaside cliff kicks a stone over the edge with a speed of 18 m/s. The cliff is 52 meters above the water's surface. How long does it take for stone to fall to the water? With what speed does it strike the water

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.