# What is the heat equation in spherical coordinates?

## What is the heat equation in spherical coordinates?

That is to say kr=kφ=kz at a point.}

**What does triple integral represent?**

Triple integrals are the analog of double integrals for three dimensions. They are a tool for adding up infinitely many infinitesimal quantities associated with points in a three-dimensional region.

**How do you find the volume of a sphere using an integral?**

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- Compute the volume of a sphere of radius r using an integral. SOLUTION. The sphere of radius r can be obtained rotating the half circle graph of the function y = √ r − x2, x ∈ [−r, r]. about the x-axis. The volume V is obtained as follows: V = ∫ r.
- −r.
- π( √ r2 − x2)2 dx = 2. ∫ r.
- π(r2 − x2)dx = (4/3)πr3.

### What are multiple integrals used for?

multiple integral, In calculus, the integral of a function of more than one variable. As the integral of a function of one variable over an interval results in an area, the double integral of a function of two variables calculated over a region results in a volume.

**How do you solve triple integration?**

Key Concepts

- To compute a triple integral we use Fubini’s theorem, which states that if f(x,y,z) is continuous on a rectangular box B=[a,b]×[c,d]×[e,f], then ∭Bf(x,y,z)dV=∫fe∫dc∫baf(x,y,z)dxdydz.
- To compute the volume of a general solid bounded region E we use the triple integral V(E)=∭E1dV.

**What is diffusion equation in heat transfer?**

Consider heat flowing along the z axis. The heat that enters the volume at z+dz is Qz and the heat that leaves the volume at z is Qz−dQz. The change in heat within the volume is then: ΔQ=Qz−(Qz−dQz)

#### Which of the following is the heat conduction equation?

Most materials are nearly homogeneous. Therefore, we can usually write k = k (T). Similar definitions are associated with thermal conductivities in the y- and z-directions (ky, kz), but for an isotropic material, the thermal conductivity is independent of the direction of transfer, kx = ky = kz = k.

**Is diffusion equation linear?**

The diffusion equation is a parabolic partial differential equation. In physics, it describes the macroscopic behavior of many micro-particles in Brownian motion, resulting from the random movements and collisions of the particles (see Fick’s laws of diffusion).

**What is the equation to calculate the amount of heat transferred?**

To calculate the amount of heat released in a chemical reaction, use the equation Q = mc ΔT, where Q is the heat energy transferred (in joules), m is the mass of the liquid being heated (in kilograms), c is the specific heat capacity of the liquid (joule per kilogram degrees Celsius), and ΔT is the change in …

## What are equations for conduction in solids?

I.C Differential Heat Conduction Equation where q″′ is the volumetric heat source and α is the thermal diffusivity, α = k/ρc. If the heat source is equal to zero, this reduces to the Fourier equation. If the temperature in the solid is invariant with respect to time, this becomes the Poisson equation.

**Is the heat equation the diffusion equation?**

There is no difference physical or mathematical . Heat equation is ONE application of the diffusion equation whether one,two or three dimensional and whether the diffusion coefficient is spatially uniform or not.No difference also between both in considering or accommodating the source/sink term.

**What is theta and Phi in spherical coordinates?**

Spherical coordinates (r, θ, φ) as commonly used in physics (ISO 80000-2:2019 convention): radial distance r (distance to origin), polar angle θ (theta) (angle with respect to polar axis), and azimuthal angle φ (phi) (angle of rotation from the initial meridian plane). The symbol ρ (rho) is often used instead of r.

### Is equation of sphere a function?

Spheres, just like circles in R2, aren’t functions since there are points in its domain which give more than one output. Functions should only return one output point at most; since the equation outputs 2 values for z for every input of x and y (with a few exceptions in its domain), then it is not a function.