Question

If an object is projected upward from the top of a 144 ft building at 112 ft per sec, its position (in feet above the ground) is blow. When does it hit the ground? h(t)-16t^2+112t+144
only answer if you really know it please I cannot get it wrong

Answer 1

When it hits the ground the height would be 0.

Set h to 0 and solve for t ( time)

0 = -16t^2 + 112t + 144 divide both sides by -16:

T^2 -7t -9

Factor the polynomial :

( t- 8.1) (t+1.1

Solve for t setting each equation to 0:

T = 8.1 or t = -1.1

Time has to be positive, so the answer is

8.1 seconds

Depending on how everything gets rounded it could also be 8 seconds.