You can put this solution on YOUR website! A ball is thrown upward with an initial speed of 24.5 m/s.
When is it 29.4 m high?
:
Using the formula: -4.9t^2 + 24.5t = h
Where
h = height in t seconds
t = time in seconds
4.9 = effect of gravity m/s
24.5 = initial upward speed m/s
:
-4.9t^2 + 24.5t = 29.4
:
-4.9t^2 + 24.5t - 29.4 = 0
:
As luck would have it, we can divide both sides by -4.9, and have simple equation
t^2 - 5t + 6 = 0
Factors easily to:
(t-3)(t-2) = 0
Two solutions
t = 2 seconds, (at 29.4 m on the way up)
t = 3 seconds, (at 29.4 m on the way down)
:
Graphically, you can see it's approx 30ft at 2 sec and 3 sec:
