# Some hints on the question please? thanks!

some hints on the question... please?!! thanks!

1. Assume that the region to the right of a certain vertical plane contains a
vertical magnetic field of magnitude 1.00 mT, and the field is zero in the region
to the left of the plane. An electron, originally traveling perpendicular to the
boundary plane, passes into the region of the field. (a) Determine the time
interval required for the electron to leave the “field-filled” region, noting that
its path is a semicircle. .

In order to find the time takes for the electron to leave the region, the displacement of the electron needs to be found
since the path is a semicircle, then displacement is 2r
so one equation will be : 2r= vt+0.5at^2
since radius r= mv/qB ... another equation..

I feel that I need some other relations between v,a, and r, inorder to solve the question... but where are the rest???
am I on the right track??

Thanks for all the help!!!

LowlyPion
Homework Helper

so one equation will be : 2r= vt+0.5at^2

Actually not. That equation is appropriate for linear motion. Your electron will be involved in a rotational trajectory, and hence you will want to consider the arc as the distance over which your electron passes.

So V = πr/t