A ball is launched horizontally from the top of a cliff with an initial velocity of 20 m/s. If the ball strikes the ground after five seconds, then (a) how high was the cliff and (b) how far from the base of the cliff will the ball land?

Point charges q1 = 51 µc and q2 = −27 µc are placed 1.0 m apart, with q2 on the right. what is the force (in n) on a third charge q3 = 19 µc placed midway between q1 and q2? (assume the positive direction is to the right. indicate the direction with the sign of your answer.)