Roger sees water balloons fall past his window. He notices that each balloon strikes the sidewalk 1.2s after passing his window. Roger's room is on the fifth floor, 25m above the sidewalk.

How fast are the balloons traveling when they pass Roger's window? Assuming the balloons are being released from rest, from what floor are they being released? Each floor of the dorm is 5.0 m high.

H = v 0 * t + gt² / 2

25 m = v o * 1.2 s + (9.81 m/s² * 1.2 s) / 2

1.2 v 0 = 17.9368

v o = 14.947 m/s (velocity of the balloons when they pass Roger's window)

When the balloons are being released: v o = 0 m/s

v = v o + g t

14.947 m/s = 0 m/s + 9.81 t

t = 14.947 m/s : 9.81 m/s²

t = 1.52 s

Time in total: 1.52 s + 1.2 s = 2.72 s

h 1 = gt² / 2 = 9.81 * 2.72² / 2 = 36.29 m

35 m ≈ the 7th floor

Answer: The balloons are being released from the 8th floor.