# Homework Help: Megnetic force problem help

1. Jul 20, 2007

### vicks

megnetic force problem help plz

A charged particle (q = +2.7 µC) moves at speed v0 = 50 m/s in the +x-direction. At x = 0 it enters a region where a constant magnetic field B = 3.4 T is directed in the +z direction ?

What are the component of electric field ?

i got the Ex and Ez which are Zero .. but i can;t figure out the Ey ?

so
(a) what is Ey ?

here are the some hint :
Use the Lorentz force law for the net force on a charged particle in a region containing both electric and magnetic fields. (The law is called the "electromagnetic force law" ). but i still can;t figure it out so plz help me out with this . thank you

If the incoming particle were replaced by one with the opposite electric charge but the same initial velocity, what electric field would be required to ensure a straight line motion? (Magnetic field is unchanged.)

(b) again what is Ey' ?

Last edited: Jul 20, 2007
2. Jul 20, 2007

### chaoseverlasting

I think there is some information missing. Is an electric field already present?

3. Jul 20, 2007

### Staff: Mentor

Or maybe they are asking what external E field would result in the particle still moving at Vo only in the x direction?

vicks, can you please type out the question exactly as it is given to you?

4. Jul 20, 2007

### rootX

I think it's equal to

=([dv/dt]*mass)/2.7

we aren't given either of them :(