- #1

- 6

- 0

## Homework Statement

A point charge Q

_{1}is distance r from the center of a dipole consisting of charges +/- q

_{2}separated by distance s. The charge is located in the plane that bisects the dipole. At this instant, assuming r>> s,

Part A: what is the magnitude of the force on the dipole?

Part B: what is the magnitude of the torque on the dipole?

**In the space provided, enter the factor that multiplies (1/ε**

_{0}) in your answer. Express this factor in terms of q_{2}, Q_{1}, s, π, and r.## Homework Equations

1. E

_{dipole}=(1/4πε

_{0})(2p/r

^{3})

2. p=qs

3. F=qE

4. τ=pEsinϑ

## The Attempt at a Solution

Part A

Substituting equation 1and 2 into equation 3

F = qE

= (q

_{2})(1/4π)(2q

_{2}s/r

^{3})

Part B

τ = pEsinϑ

= (q

_{2}s)(1/4π)(2q

_{2}s/r

^{3})sin90º

= (q

_{2}s)(1/4π)(2q

_{2}s/r

^{3})

I got a feeling I'm missing an important step involving Q

_{1}in both parts.

Help's much appreciated =)