There are two situations in which it possible for a charged particle to be in a magnetic field but not experiencing a magnetic force. What are they? (Hint: Looking at the equation for magnetic force will help!)

Question

There are two situations in which it possible for a charged particle to be in a magnetic field but not experiencing a magnetic force.  What are they?  (Hint: Looking at the equation for magnetic force will help!)

mtalhahassan2 · Answer

@gollywolly can you help me with this one? plz

gollywolly · Answer

hmmm not tooo sure but I will help look stuff up.

mtalhahassan2 · Answer

@gollywolly thnx in advance thou

gollywolly · Answer

http://physics.stackexchange.com/questions/165752/understanding-magnetic-force-on-charged-particle

gollywolly · Answer

One appears to be if it is stationary relative to the object producing the field.

mtalhahassan2 · Answer

yea..

mtalhahassan2 · Answer

is the other one be:
The Lorentz force law is
F=q[E+v×B]
Only a moving particle experiences a magnetic force, but the electric force is always felt.

gollywolly · Answer

Yeah E field is always felt. It is a cross product so it would be when theta is equal to 0?

mtalhahassan2 · Answer

are you sure is it a cross product?

gollywolly · Answer

Pretty sure.

gollywolly · Answer

Every search is confirming that.

gollywolly · Answer

Yeah that all makes sense. The force relys on the lorence factor which has to deal with velocity so when it is zero the force is zero and when theta is 0 sin is zero.

mtalhahassan2 · Answer

okay so..this be the second situation right?

gollywolly · Answer

Yeah. I'm pretty positive that those are both.

mtalhahassan2 · Answer

well thnx again!

gollywolly · Answer

No problem