Problem 20:  A teenager on a bridge throws a rock with an initial speed of 11.49m/s . The release point is a distance of 22.3m above the water below. Air resistance is negligible. Assume g=9.81m/s . Part (a)  If the rock is thrown straight upward, with what speed will it hit the water?  Part (b)  If the rock is thrown horizontally, with what speed will it hit the water? Part (c)  If the rock is thrown downward (not released from rest), with what speed will it hit the water? Part (d)  In which scenario does the rock strike the water with the greatest speed?  When the rock is thrown straight downward    When the rock is thrown straight upward   It does not matter which direction the rock is thrown.   When the rock is thrown horizontally