Question 608446
Given:
h = 2 + 45t - 16t^2
set h to 2 and solve for t:
2 = 2 + 45t - 16t^2
0 = 45t - 16t^2
0 = t(45 - 16t)
.
t = {0,45/16}
t = {0,2.81}
answer: 2.8 seconds