The ball describes a parabola, as you can see in the attached picture. So, the point where the ball strike the ground is the point where the parabola meets the x axis. In fact, the x-axis is the set of points where y=0, which means that the ball has height 0 or -again- it hits the ground.
So, we have to set y=0 in our equation and look for the positive solution. We have

And the positive solution is

So that's the distance from the child where the ball strikes the ground.
For the table
10 —> 4
1 —> 0.4
20 —> 8
40 —> 16
39 —> 15.6
It should be 11. hope this helps :)
Answer:
4
Step-by-step explanation:
4ways
circle with centre
spare
The divergence theorem applies since

is a closed surface. We have

where

is the space enclosed by the surface

. The divergence of the given vector field is

So we can write the volume integral (in spherical coordinates) as