Question 344463
Set h to zero and solve for t:
h= -4.9t^2 + 14.0t + 2.1
0= -4.9t^2 + 14.0t + 2.1
Apply quadratic formula to get:
t = {-0.143, 3}
You can toss out the negative solution leaving:
t = 3 seconds
.
Details of quadratic to follow:
*[invoke quadratic "t", -4.9, 14, 2.1 ]