An electron is projected with an initial speed v0 = 1.10 x 10⁶ m/s into the uniform field between the parallel plates. the distance between the plates is 1 cm and the length of the plates is 2 cm. assume that the field between the plates is uniform and directed vertically downward, and that the field outside the plates is zero. the electron enters the field at a point midway between the plates. e = n/c
(a) if the electron just misses the upper plate as it emerges from the field, find the magnitude of the electric field.
(b) suppose that the electron is replaced by a proton with the same initial speed. would the proton hit one of the plates?

a)

b) No

Explanation:

A) Because the electron is affected by an acceleration force in this case by the electric field, we can use the formulas of 2-dimension movement.

We will assume the electron missed the upper plate, so we need to calculate the time to travel all the way through the plate, that is:

so:

the electron experiences an accelerated motion in the vertical direction, so we can obtain the acceleration of the electron:

so:

now we can use the relation:

Now we can calculate the electric field:

B) Because the proton has the same charge but positive it will go in the opposite direction, so because we assume the electron didn't touch the plate, the proton won't.

answer: electrons

at positions a, g kinetic energy is maximum.

at position d, potential energy is maximum.