Question

Roger sees water balloons fall past his window. He notices that each balloon strikes the sidewalk 1.01 s after passing his window. Roger's room is on the third floor, 15 m above the sidewalk.

How fast are the balloons traveling when they pass Roger's window?

Express your answer to three significant figures and include the appropriate units.

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.

Express your answer as an integer.

Answer 1

Answer:

a) Speed of the balloons traveling when they pass Roger's window = 9.9 m/s

b) The balloons are being released from a floor away from Rogers' floor; so, the fourth floor.

Explanation:

We assume that the effects of air resistance are negligible.

Using the equations of motion,

g = 9.8 m/s², y = H = 15 m,

Initial velocity at his window level, u = ?

Time of fall (measured from his window to the ground), t = 1.01 s

a) y = ut + gt²/2

15 = u(1.01) + 9.8(1.01²)/2

1.01 u = 15 - 4.998

u = 10/1.01

u = 9.9 m/s

b) Starting from rest, initial velocity = u = 0 m/s, g = 9.8 m/s²

Now, let y = distance from where the balloons were released up to Rogers room.

v = 9.9 m/s

v² = u² + 2gy

9.9² = 0 + (2×9.8)y

y = 98.01/19.6 = 5 m

Each floor is 5 m high.

Since the distance from the balloons' release to Rogers' window is 5m, the balloons were released from the floor directly above his own, the fourth floor.