Answer:
4 seconds
Explanation:
We have a quadtratic equation, that is, we have a function to the highest degree of x^2.
When solving this, we can either solve using the quadratic equation, or by solving for X which would be the easiest and quickest way to do it.
256 -16x^2=0
-16x^2=-256
x^2=16 (divide both sides by -16)
Which leaves x=4 as your answer.
To check this, we can simply input 4 back into the equation, and we will find that it does indeed equal 0.
To further visualize this, when we solve the equation for x, we are finding where the x value that intersects the x axis. We are finding where x=0, or when it touches the ground.