1. Roger sees water balloons fall past his window. He notices that each balloon strikes the sidewalk 0.77 ss after passing his window. Roger's room is on the fourth floor, 20 mm above the sidewalk.

a. How fast are the balloons traveling when they pass Roger's window?Express your answer using two significant figures.

b. Assuming the balloons are being released from rest, from what floor are they being released? Each floor of the dorm is 5.0 mm high.Express your answer as an integer.

2. A ball is dropped from the top of a 47.0 mm -high cliff. At the same time, a carefully aimed stone is thrown straight up from the bottom of the cliff with a speed of 25.0 m/sm/s . The stone and ball collide part way up.

How far above the base of the cliff does this happen?