Rotational Volume - spherical cap, solids, and napkin ring problems

In summary, the conversation discusses the topic of rotational volume in Calculus II and the speaker's struggles with using the disk, washer, and shell methods to solve related problems. They ask for help and provide an example of using the cylindrical shell method to solve a specific problem.
  • #1
emc92
33
0
We are doing rotational volume in Calculus II right now. I know the basic rules for the disk, washer, and shell methods, but I'm having trouble getting started with these questions. I'm not sure how to set up the equations. Any sort of help would be great.

Thanks so much!
 

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  • #2
For the first and third example i have no clue. I am doing this same stuff in class now to, and find those kind of problems so difficult.

Second one, i believe you would go:

using the cylindrical shell method

2pi (integral from 0 to 4 of x(sinx) dx

thats just what i think, i could be off!
 

Related to Rotational Volume - spherical cap, solids, and napkin ring problems

1. What is rotational volume?

Rotational volume is the amount of space occupied by a three-dimensional object when it is rotated around a fixed axis. This concept is commonly used in geometry and physics to calculate the volume of objects with rotational symmetry, such as spheres, cylinders, and cones.

2. What is a spherical cap?

A spherical cap is a portion of a sphere that is bounded by a plane. In other words, it is a piece of a sphere that has been cut off by a flat surface. The volume of a spherical cap can be calculated using the formula V = (πh^2/3)(3R - h), where h is the height of the cap and R is the radius of the sphere.

3. How do you determine the volume of a solid with rotational symmetry?

To determine the volume of a solid with rotational symmetry, you can use the disk or washer method. This involves dividing the solid into infinitesimally thin slices, rotating each slice around the axis of rotation, and then adding up the volumes of all the slices. This method is commonly used to find the volume of objects like cylinders, cones, and spheres.

4. What is a napkin ring problem?

A napkin ring problem is a type of rotational volume problem that involves finding the volume of a solid that is formed by rotating a two-dimensional shape around a fixed axis. This shape is often referred to as a napkin ring because it resembles the ring that holds a napkin in place.

5. How can rotational volume be applied to real-world situations?

Rotational volume has many practical applications, such as in architecture, engineering, and manufacturing. It can be used to calculate the volume of objects like pipes, bottles, and containers, as well as to design and analyze structures with rotational symmetry, such as bridges and towers.

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