Velocity or acceleration of an electron through 300 volts.?

Question

I need to figure out the velocity of this electron and all i know is that it accelerated from rest through 300V. How can I do this?

Answer 1

Remember that potential energy is QV where Q is charge and V is potential difference. Also kinetic energy is mv²/2 so setting these equal to each other and simplifying
v = √(2qV/m) where q is the charge of one electron and m is its rest mass. Then
v = √(2*(1.6*10^(-19)*300/9.11*1-^(-31)) =
1.0265*10^7 m/s

HTH ☺


Doug