Question 988387
Find the time to the highest point and double it.
That is the vertex of a quadratic equation, which x value (t here) is -b/2a=-400/-32=12.5
So the vertex is at 12.5 seconds, and the time to Earth is 25 seconds.
The maximum height will be 2500 feet.
{{{graph(400,400,-10,30,-100,3000,-16x^2+400x)}}}