Solve using integration and solids of revolution
The metal cover for a piece of machinery is 0.90 m in length, the radius of one end is 20 cm and the radius of the other end is 30cms as shown in the following diagram:
I have calculated the volume for the cylinder section but am having trouble with frustum section
You can think of the truncated cone as being generated by the revolution of a straight line that goes through points $(-45,20)$ and $(0,30)$, i.e., $y=30-\frac{10}{9}x$.