The volume of a cone uses the following formula:

Our diameter is 20 feet, so divide this by 2 to find the radius:

We now have all of our values need to fill in the formula. Plug in these values:




The volume of the cone is 
1780 cubic feet.
 
        
        
        
Answer:
2nd choice: The ball first bounced up to the height of 2 meters, and then falls 2 meters towards the ground
Step-by-step explanation:
 
        
             
        
        
        
Explanation:
using the parabola formula:
y = a(x-h)² + k²
vertex = (h, k)
We are given a parebola equation of: y = x²+9
comparing both equations to get the vertex:
y = y
a = 1
(x-h)² = x² 
x² = (x + 0)²
(x-h)² = (x + 0)²
h = 0
+k = +9
k = 9
The vertex of the parabola as (x, y): (0, 9)