how long it will take for the ball to hit the ground?

Question

A ball is thrown upwards with an initial velocity of 48 feet per second from the top of a small bridge that is 64 feet in the air. determine how long it will take for the ball to hit the ground?

 

The equation used to model the height of an object after t seconds is given by the function h(t)=-16t2 + V0t + S0, where v0 is the initial velocity applied on an object and s0 is the initial height

Answer 1

v₀ = 48 ft/sec

s₀ = 64 feet

The ball hits the ground when h(t) = 0

 

0 = -16t² + 48t + 64        Divide both sides by 16

0 = -t² + 3t + 4               Factor out the "-"

0 = -(t² - 3t - 4)               Factor by FOIL

0 = -(t - 4)(t + 3)

 

The solutions are 4, and -3. Time cannot, at least here, be negative.

 

The ball hits the ground after 4 seconds.