Answer:
8.51 seconds
Step-by-step explanation:
Time to reach maximum height
=( Usin90)/2g
= 32/2*9.81
= 32/19.62
= 1.63 s
Max height = U²Sin²tita/g
= 32²/9.81
= 1024/9.81
= 104.38ft
Total height=104.38 + 128= 232.38
Time to fall back to the ground using the formula
h = ut+(1/2)gt²
U= 0
H= 232.38
g = 9.81
(232.38 *2 )/9.81= t²
47.376= t²
t = 6.88 s
Total time taken to hit ground
= 6.88 + 1.63
= 8.51 seconds