From her bedroom window a girl drops a water-filled balloon to the ground, 4.77 m below. If the balloon is released from rest, how long is it in the air?
We need to use the equation x = vt + (1/2)at^2. We know x = 4.77, v = 0, and a = 9.81m/s^2. Plug in the values.
4.77 = (0)t + (1/2)(9.81)t^2
Solve for t.
4.77 = (4.905)t^2
0.972 = t^2
t = (sq.rt)_/0.972
t = 0.985
So it's in the air 0.985 seconds.
