# What speed do the electrons have when they strike the screen?

In a typical color television tube, the electrons are accelerated through a potential difference of 25,000 Volts. What speed do the electrons have when they strike the screen? (qe = 1.6 x10-19 C, me = 9.1 x10-31 kg)

## Answers and Replies

mgb_phys
Science Advisor
Homework Helper
What is the energy to move a charge through a voltage?
Then if no energy is lost this becomes kinetic energy

These are the possible answers.
a. 0.55c.
b. 0.09c.
c. 0.30c.
d. 0.90c.

mgb_phys
Science Advisor
Homework Helper
I know the answer - the point is for you to learn something

I don't know what formula to use.

mgb_phys
Science Advisor
Homework Helper
You need an equation with voltage, charge and energy - have you come across electron-volt?

Do you know the equation for kinetic energy?

No, I just need the exact formula then I will know what to do from there.

Dude, just open the nearest physics book available and go to the section on voltage differences between two points in space, you'll know which formula to use right away

You can even google it.