CLYINDRICAL coordinates of volume bound by z=r and z^2+y^2+x^2=4

In summary, the problem is to find the smaller volume bound by a cone and a sphere using cylindrical coordinates. The attempt at a solution includes calculating the limits for r, theta, and z and obtaining an answer of 8 pi, which is different from the answer using spherical coordinates. Guidance is needed for determining the correct limits.
  • #1
Unemployed
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Homework Statement



Find the smaller volume bound by cone z=r and sphere z^2+y^2+x^2=4 using cylindrcal coordinates

Homework Equations



dV=r-dr d-theta dz

The Attempt at a Solution



Limits on r: z to sqrt (4-z^2)
limits on theta: 2pi to 0
limits on z: 2-0

Did this and got 8 pi, not the same answer with spherical.
Need guidance on limits.

 
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  • #2
Hi Unemployed! :smile:

(have a theta: θ and a pi: π and a square-root: √ and try using the X2 icon just above the Reply box :wink:)
Unemployed said:
Limits on r: z to sqrt (4-z^2)

Not for the cone bit :wink:
 
  • #3
tiny-tim said:
Hi Unemployed! :smile:

(have a theta: θ and a pi: π and a square-root: √ and try using the X2 icon just above the Reply box :wink:)


Not for the cone bit :wink:

For r = 0 to √2 ?
 
  • #4
No, the limit for r will still depend on z, but linearly instead of "curvily". :wink:
 

FAQ: CLYINDRICAL coordinates of volume bound by z=r and z^2+y^2+x^2=4

What are cylindrical coordinates?

Cylindrical coordinates are a type of coordinate system used to represent points in three-dimensional space. They consist of three components: radius (r), angle (θ), and height (z). These coordinates are commonly used in physics and engineering applications.

How do you convert from Cartesian coordinates to cylindrical coordinates?

To convert from Cartesian coordinates (x, y, z) to cylindrical coordinates (r, θ, z), you can use the following equations:r = √(x² + y²)θ = arctan(y/x)z = z

What is the volume of a cylinder in cylindrical coordinates?

The volume of a cylinder in cylindrical coordinates is given by V = πr²h, where r is the radius and h is the height. In this case, the height is represented by z, and the radius can be found by setting z=r in the equation z²+y²+x²=4 and solving for r.

How do you find the boundaries for a volume in cylindrical coordinates?

In this scenario, the boundaries are given by z=r and z²+y²+x²=4. To find the boundaries for a volume in cylindrical coordinates, you can use the equations r = √(x² + y²) and z = z. These equations will give you the range of values for r and z that will define the boundaries of the volume.

What is the significance of the volume bound by z=r and z²+y²+x²=4 in cylindrical coordinates?

The volume bound by z=r and z²+y²+x²=4 represents a cylinder with a radius of √(4-z²) and a height of z. This can be visualized as a circular disk with varying height along the z-axis. This volume can be useful in applications such as calculating the volume of a cylindrical tank or determining the displacement of a cylindrical object in fluid dynamics.

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