# Homework Help: Acceleration of an electron

1. May 16, 2004

### 3.14159265358979

the mass of the electron is 9.1x10^-31 kg and its charge is -1.6x10^-19 c. Calculate the acceleration of an electron that is in a constant electrin field who intensity is 5.10x10^2 N/C upwards. (answer according to back: 9x10^13 m/s^2 (down))

thank you very much.

2. May 16, 2004

### Staff: Mentor

Where are you stuck? (Show your work.)

You'll need to know the definition of electric field and Newton's 2nd law.

3. May 16, 2004

### 3.14159265358979

i'm stuck on the acceleration part? how do i get it into the formula?
i know electric field = (kq) / r^2 and F = ma? thanks

4. May 16, 2004

### Staff: Mentor

That formula is for the electric field of a point charge: you don't need it for this problem. In this problem, the electric field is given. What you do need to know is how much force will that field exert on the electron. The magnitude of the force is given by F = qE.

5. May 16, 2004

### 3.14159265358979

yes, of course! thanks i understand know...