Homework Help: Charging an airplane

1. Jan 28, 2004

Spectre32

AN airplane is flying through a cloud. The airplane is at 2100M and the top height of the cloud is 4100M @ 23 C. The bottem of the cloud is 500m @-47 C. What is the strength of the electric field E at the aircraft.

Now I broke it up into to parts, for the top of the cloud and the bottem.

Top of the cloud:

Using coulumbs law: 8.98755 x 10^9* 23/ 4100-2100) = 1.03357e8

Bottem of the cloud:

8.98775 x 10^9 * 47/ 2100-500 = 2.64009e9

I added both of those up and i submited my answer and it said it was wrong. Can anyone aid me?

2. Jan 28, 2004

chroot

Staff Emeritus
The distance should be squared.

Also, make sure you put your parentheses in the right place. I assume that you are actually typing the numbers into your calculator correctly, but just be careful.

8.98775 * 10^9 * 47 / 2100 - 500

is not the same as

(8.98775 * 10^9 * 47) / (2100 - 500)

- Warren

3. Jan 28, 2004

Staff: Mentor

Assuming that the charged clouds can be treated as point sources of the electric field: use $E=\frac{kq}{r^2}$. (You forgot to square your distances.)

4. Jan 28, 2004

Spectre32

crap..... wow i'm so retarded thanks alot doc