(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Two dipoles as in pic below a distance r apart, find the torque applied to each dipole due to the other.

[tex]\uparrow1 ------------2\rightarrow[/tex]

2. Relevant equations

[tex]\itshape \vec{p}=p(cos\:\theta \hat{r}-sin\:\theta\hat{\theta})[/tex]

[tex]\itshape \vec{E}=\frac{p}{4\pi\epsilon_{0}r^{3}}\: (2cos\:\theta\hat{r}+sin\:\theta\hat{\theta})[/tex]

[tex]\itshape \vec{N}=\vec{p}\:X\:\vec{E}[/tex]

3. The attempt at a solution

well i only am concerning myself with the non constants in the cross product.

[tex]\itshape \vec{N}=\vec{p_{2}}\:X\:\vec{E_{1}}[/tex]

[tex]\itshape (cos\:\theta\hat{r}-sin\:\theta\hat{\theta})X(2cos\:\theta\hat{r}+sin\:\theta\hat{\theta})[/tex]

ok this is where i am confused... do i use \theta as angle under the z axis for the direction the dipole and electric field are pointing, or do i use them for angles of separation or what? if i use them for angle under the z axis for the vector it is pertaining to i get the torque will be [tex]-3cos\:\theta sin\:\theta sin \:\phi\hat{i}+3cos\:\theta sin\:\theta cos \:\phi\hat{j}[/tex], which applying angles under z axis is 0. But that isn't what the answer should be.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Torque on/due to dipoles.

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**