Question

If an object is dropped from a height of 256 feet, the function h(t)=-16t^2+256 gives the height of the object after t seconds. When will the object hit the ground?

Answer 1

Solve the quadratic equation for h(t) = 0 Then
16t²=256
t=√256/16 = 4s

Answer 2

Answer: The object will hit the ground after 4 seconds

Explanation:

Hi, when the object hits the floor the height h (t) is equal to 0.

So, to answer this we have to solve for t substituting h(t)=0

h(t)=-16t^2+256

replacing:

0= -16t^2+256

Solving for t:

16t^2= 250

t^2 = 250/16

t = √15.625

t= 3.95 ≅4 seconds

Feel free to ask for more if needed or if you did not understand something.