Charged particle in a cloud chamber?

[chem_is_lovex]

Homework Statement

when a charged particle enters a magnetic field in a cloud chamber, why does it move in a circular path instead of straight line? I have no idea why. please help

Homework Equations

The Attempt at a Solution

it has something to do with the r changing? as I said, I have no idea.

 

[pgardn]

Homework Statement

when a charged particle enters a magnetic field in a cloud chamber, why does it move in a circular path instead of straight line? I have no idea why. please help

Homework Equations

The Attempt at a Solution

it has something to do with the r changing? as I said, I have no idea.

Do you know the rules governing moving charges in uniform B fields and how the direction of the Force is oriented? Some use the right hand rule? Is this familiar?

 

[inutard]

As pgardn mentions above, a magnetic field interacts with a charged particle in quite a peculiar way. Similar to a ball being spun on a string, the magnetic field exerts a centripetal force to the component of the charge's velocity that is perpendicular to the field (whew. that sounded like a lot to digest!). What this basically means is that the magnetic force exerted on the charge always alters the charge's path, making it move in a circular path instead of a straight line.