Question

A bowling ball rolls off the edge of a cliff, moving horizontally at 20 m/s. I have to plot the position of the bowling ball on an x y axis for every one second. X is horizontal distance and Y is vertical distance on the graph. We are using 10 m/s squared for gravity instead of 9.8 m/s squared. 

Answer 1

For counting x you use simple equation for the distance covered by the object when it moves with constant velocity:
$s=v*t$
that gives you 20m after 1st second, 40 m after 2nd second, 60 m after 3rd second and so on.

For counting y you have to use the equation for the distanced covered by the object moving with constantly accelerating velocity (symbols refering to vertical movement):
$h=g\frac{t^{2}}{2}$
that gives you 5m after 1st second, 20m afters 2nd second, 45m after 3rd second and so on.
Add minus signs before y positions to receive graph presenting the movement of the ball.
So the points are: P1=[20,-5], P2=[40,-20], P3=[60,-45] and so on... Pn=[x,y].