Answer:
6.22 sec
Explanation:
h(t) = 105t-16t^2
For values of t for which height will be 34 feet can be obtained by substituting 34 in place of h(t) and solving for t
34=105t-16t^2, using quadratic formula we have t=1/32*(105±sqrt(8849)) which translates to - 0.34sec and 6.22sec but as time can't be negative, time is 6.22sec