an object is thrown upward from a height of 70 feet. t second after it is released, the object is h=-16t^2+40t+70 feet above the ground. how many seconds does it take until the object hits the ground?

Answer 1

Tr = -Vo/g = -40/-32 = 1.25 s. = Rise
time or time to reach max ht.

h = -16*1.25^2 + 40*1.25 + 70 = 95 Ft.

h = 0.5g*t^2 = 95
16t^2 = 95
t^2 = 5.94
Tf = 2.44 s. = Fall time.

Tr+Tf = 1.25 + 2.44 = 3.69 s. = Time to
reach gnd.