# Energy of a System

## Homework Statement

In an electron microscope, there is an electron gun that contains two charged metallic plates 3.05 cm apart. An electric force accelerates each electron in the beam from rest to 9.70% of the speed of light over this distance. (Ignore the effects of relativity in your calculations.)

(a) Determine the kinetic energy of the electron as it leaves the electron gun. Electrons carry this energy to a phosphorescent viewing screen where the microscope's image is formed, making it glow.
J

(b) For an electron passing between the plates in the electron gun, determine the magnitude of the constant electric force acting on the electron.
N

(c) Determine the acceleration of the electron.
m/s2

(d) Determine the time interval the electron spends between the plates.
s

## Homework Equations

So far only KE=.5mv^2

## The Attempt at a Solution

A) KE=.5mv^2

Where m = mass of the electron...9.10938215E-31kg
and V = 9.7% of the speed of light...29079868.43
KE=3.8516E-16

Is that correct for A?

Second I'm a bit lost on where to go from here. I know it has to do with the length in meters (.0305m). Can anyone help please?