set h=0 and solve for t for time when it hits the ground

-16^2 + 48t + 64 =0, divide by -16, to get

t^2 -3t -4 =0, factor and set each factor =0

(t-4)(t+1) = 0

t = 4 seconds, ignore the negative solution

Joon Y.

asked • 02/12/21An object is thrown upward from the top of a 64-foot building with an initial velocity of 48 feet per second. The height h of the object after t seconds is given by the quadratic equation h = -16t^2 + 48t + 64. When will the object hit the ground?

Follow
•
1

Add comment

More

Report

set h=0 and solve for t for time when it hits the ground

-16^2 + 48t + 64 =0, divide by -16, to get

t^2 -3t -4 =0, factor and set each factor =0

(t-4)(t+1) = 0

t = 4 seconds, ignore the negative solution

Ask a question for free

Get a free answer to a quick problem.

Most questions answered within 4 hours.

Find an Online Tutor Now

Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.