Question

Amir stands on a balcony and throws a ball to his dog, who is at ground level. The ball's height (in meters above the ground), x seconds after Amir threw it, is modeled by: h(x)=-(x-2)^2+16 How many seconds after being thrown will the ball hit the ground?

Answer 1

The other person's answer of '6' is correct, but only when your question specifically asks:

How many seconds after being thrown will the ball hit the ground?

Answer 2

When the ball hit the ground, the height of the ball will be zero. So using the value of h(x) as zero in the given equation, we can find the time in which the ball will hit the ground.


`0=-(x-2)^(2)+16 \\ \\ (x-2)^(2)=16 \\ \\ x-2= √(16) \\ \\ x-2=4 \\ \\ x=6`

This means the ball will hit the ground 6 seconds after Amir threw it