# Question #d8707

##### 1 Answer

Jan 27, 2018

#### Explanation:

We are given that the height,

The problem wants us to find the time,

Therefore, we can plug in

#f(x) = -5x^2 + 200#

#color(red)50 = -5x^2 + 200#

#color(red)50 - color(blue)200 = -5x^2 + cancel200 - cancelcolor(blue)200#

#-150 = -5x^2#

#(-150)/color(blue)(-5) = (cancel(-5)x^2)/cancelcolor(blue)(-5)#

#30 = x^2#

#color(blue)(sqrtcolor(black)(30)) = color(blue)(sqrtcolor(black)(x^cancel2)#

#sqrt30 = x#

So the ball will be 50 meters above the ground at

*Final Answer*