Question

An electron is traveling horizontally from E to W in a region of space where the Earth's magnetic field is directed horizontally toward the north. What is the direction of the magnetic force on the electron?

Answer 1

WKT. F = q ( V x B)
where F -->Magnetic force V-->direction of velocity B-->Magnetic Field

In our case, velocity is from E to W. , Magnetic field along Earth

Using this rule --> http://en.wikipedia.org/wiki/Cross_product#Definition
We get Direction of F = - (Along negative z axis.)
Now you will be wondering why F = - (Along negative z axis.)
The reason is , since q, charge of electron, is negative, therefore
F = - (Along negative z axis.) = Along Positive z axis

Answer 2

east
south
The magnetic force on the electron is zero.
down
up
north
so which 1 is correct?

Answer 3

Along posititve z-axis --->UP

Answer 4

thnx