Question 371009
h(t)=-16t square -50t+164
When it reaches the ground the "height" is zero
so, set h(t) to zero and solve for t:
0=-16t^2 -50t+164
0=16t^2 + 50t - 164
0=8t^2 + 25t - 82
Applying the "quadratic formula" we find that
t = {2, -5.125}
Throw out the negative answer leaving
t = 2 seconds
.
Details of quadratic to follow:
.
*[invoke quadratic "t", 8, 25, -82 ]