A rock of mass 30 g strikes a car windshield while the car is traveling on a highway. Estimate the force of the rock on the windshield. You will need to estimate the collision time (i.e., the time that the rock is in contact with the windshield). For comparison, the collision time for a baseball-bat collision is approximately 0.001 s, while the time for a tennis racket-ball collision is about 0.01 s.