# Homework Help: Charge in relativity

1. Apr 10, 2012

### chaotic

A charge q is placed at a distance d from an innite charged wire carrying lamdba charge per
unit length.
(a)What is the force acting on the charge q? (b)Find the force on charge q with respect
to an observer moving moving at speed u along the wire.

Last edited: Apr 10, 2012
2. Apr 10, 2012

### elfmotat

E and B fields transform according to the Lorentz Transformation:

$$\mathbf{E}'=\gamma (\mathbf{E}+\mathbf{v}\times \mathbf{B})+(1-\gamma)\frac{\mathbf{E}\cdot \mathbf{v}}{v^2}\mathbf{v}$$

$$\mathbf{B}'=\gamma (\mathbf{B}-\frac{1}{c^2}\mathbf{v}\times \mathbf{E})+(1-\gamma)\frac{\mathbf{B}\cdot \mathbf{v}}{v^2}\mathbf{v}$$

3. Apr 11, 2012

### locivert

In a,there is no relativistic force!

Last edited: Apr 11, 2012