A student drops a rock from a bridge to the water 11.6 m below. With what speed does the rock strike the water? The acceleration of gravity is 9.8 m/s 2 . Answer in units of m/s.

Awind turbine is rotating counterclockwise at 0.5 rev/s and slows to a stop in 10 s. its blades are 20 m in length. (a) what is the angular acceleration of the turbine? (b) what is the centripetal acceleration of the tip of the blades at t=0s? (c) what is the magnitude and direction of the total linear acceleration of the tip of the blades at t=0s?