# Electric field

1. Feb 4, 2004

### pringless

The electron gun in a televeision tube is used to accelerate electrons (mass of 9.10939 x 10^-31 kg and charge of -1.60218 x 10^-19 C) from rest to 2 x 10^7 m/s within a distance of .053 m. What electric field is required?

2. Feb 5, 2004

### ShawnD

The question only looks complicated because of the big (or small) numbers. You are given a change in velocity, a distance, and a charge.

First find the acceleration on the electron with this equation.

$$V_f^2 = V_i^2 + 2ad$$

Now find the force on the electron with this equation

$$F = ma$$

Now find the electric field with this equation

$$E = \frac{F}{q}$$

Last edited: Feb 5, 2004