Answer:
Two methods both tell us the ball is at 20 feet height at 0.783 seconds going up and 1.28 seconds on the way down.
Step-by-step explanation:
The question can be answered by either calculation or by graphing.
Calculation:
Set the equation to h = 20 feet and solve with the quadratic equation.
h= 4 + 33t - 16t^2
4 + 33t - 16t^2 = 20
- 16t^2 + 33t + 4 = 20
- 16t^2 + 33t - 16 = 0
I find solutions of 0.779 and 1.28 seconds.
Graphing:
See the attached graph.
The graph shows solutions of 0.783 and 1.28 seconds.
Both methods show the ball to be at 20 feet height at 0.783 seconds going up and 1.28 seconds on the way down.
