Answer:
The volume of the ball with the drilled hole is:
Step-by-step explanation:
See attached a sketch of the region that is revolved about the y-axis to produce the upper half of the ball. Notice the function y is the equation of a circle centered at the origin with radius 15:
Then we set the integral for the volume by using shell method:
That can be solved by substitution:
The limits of integration also change:
For x=5:
For x=15:
So the integral becomes:
If we flip the limits we also get rid of the minus in front, and writing the root as an exponent we get:
Then applying the basic rule we get:
Since that is just half of the solid, we multiply by 2 to get the complete volume:
