Question

-

Answer 1

first, velocity = ds/dt = d(-16t^2+144)/dt =....
then, when it hits the ground, s=0
solve for t in -16t^2+144 = 0
put t hitting the ground back in the ds/dt will give velocity when hitting da ground :)

Answer 2

ok i got -96

Answer 3

correct: the - sign means its going down :)

Answer 4

thanks for the help!!

Answer 5

welcome :)