# Electromagnetism qs! please help!

## Homework Statement

An electron is accelerated horizontally from rest in a television picture tube by a potential difference of 10,000 V. It then passes between two horizontal plates 5.0 cm long and 1.0 cm apart which have a potential difference of 200 V. At what angle θ will the electron be traveling after it passes between the plates?

-ΔEE = ΔEK
qΔV = 1/2mv^2

## The Attempt at a Solution

-ΔEE = ΔEK
qΔV = 1/2mv^2
√ (2qΔV)/(9.1*10^-31kg) = v
√ (2(1.6*10^-19 C)(10 000V))/ (9.1*10^-31kg) = v
5.92*10^7 = v
-so i calculated the speed of the electron before passes through the plates. i don't know what to do next.. a step-by-step solution would be appreciated, thanks in advance

## Answers and Replies

Suppose that the electric field runs upwards. It's field strength is calculated from E = U/d, where U is the potential difference and d the distance between the plates. The electric force exerted on the electron is F = QE = QU/d. From here on, use what you know about mechanics and movement to find the components of the resultant velocity to find the angle.