Answer:
Explanation:
Givens
Time taken to go down + time taken for the sound to come up = 1.17 seconds.
d = 7.92 m
a = 9.81 m/s^2
t (see below)
vi = ???
Solution to How long it takes to come back up.
v = 343 m/s
d = 7.92 meters
t = ?
t = d/v
t = 7.92 m / 343 m/s
t = 0.0231 seconds.
Solution to time taken to go down.
Time_down = 1.17 - 0.0231
time_down = 1.147 seconds
Solution to vi
d = vi*t + 1/2 a t^2
7.92 = vi*1.147 + 1/2 * 9.81 * 1.147^2
7.92 = vi*1.147 + 6.452 Subtract 6.452 from both sides.
7.92 - 6.452 = 1.147*vi
1.468 = 1.147 * vi Divide by 1.147
1.468 / 1.147 = vi
1.279 m/s = vi
