# Calculate the gain in kinetic energy of each electron.

• May 8th 2008, 08:48 AM
looi76
Calculate the gain in kinetic energy of each electron.
Question:
The electrons in a TV tube are accelerated by a p.d. of $20 \ kW$ between the filament and the screen. The charge of the electron is $1.6x10^{-19} C$. Calculate the gain in kinetic energy of each electron.

Don't know which equation to use!, need help
• May 8th 2008, 06:25 PM
topsquark
Quote:

Originally Posted by looi76
Question:
The electrons in a TV tube are accelerated by a p.d. of $20 \ kW$ between the filament and the screen. The charge of the electron is $1.6x10^-19 C$. Calculate the gain in kinetic energy of each electron.

Don't know which equation to use!, need help

$W = \Delta K$

You are told the amount of work done on each electron, 20 kW.

Is it possible you meant that the potential difference is 20 kV? In that case,
$W = qV = \Delta K$

-Dan