- #1

RabbitWho

- 153

- 18

1. Homework Statement

1. Homework Statement

Find the force of repulsion between two point charges of +1C and +3C if they are placed 1 m apart in a vacuum. On which charge is the greater force?

So here is what I know

ε=8.9x10

^{-12}

π = 3.14

d = 100 cm

q1 = 1

q2 = 3

cats are soft and warm

## Homework Equations

here is the formula I have to use

F= 1/4πε

_{0}Q

_{1}Q

_{2}/d

^{2}

I can't find pi on the thing. Is this supposed to be pi: π?It looks like a Russian L. This is hard enough without alternate fonts.

## The Attempt at a Solution

This is going to be my fourth time trying this.

The correct answer should be 2.682 x 10

^{10}

Am I right in thinking that 10

^{-2}x 10

^{-2}=10

^{-4}? It's just 100 x 100 = 10,000, right?

1 (1 x 10

^{-6}) ( 3x 10

^{-6})

_______________________________________________

4π(8.9 x 10

^{-12})(100)

Here's my attempt at solving what's above the line:

3 x 10

^{-12}

________________________________

4π(8.9 x 10

^{-12})(100)

I'm less confident about what's below. Do I multiply pi by 4 first?

3 x 10

^{-12}

________________________________

**12.5**(8.9 x 10

^{-12})(100)

Like that?

Am I right in thinking that 8.9 x 10

^{-12}x 100 = 8.9 x 10

^{-14}?

So now I have

3 x 10

^{-12}

______________________________

12.5 (8.9 x 10

^{-14}) 3 x 10

^{-12}

____________________________

1

**06**.8 x 10

^{-14})

So there are 2 zeros there that I've put in bold that I think I have to get rid of, and I'm going to add them onto that little -14

1

**.**068 x 10

^{-16}. Is that right? 3 x 10

^{-12}

___________________________

1

**.**068 x 10

^{-16}

Now there are loads of zeros above and below the line, am I right in thinking I can cross them out? the difference between -12 and -16 is 4, so I'll get rid of the -12 all together and leave -4 below.

3 x 10

_________________________

1

**.**068 x 10

^{-4}

It occurs to me that 3 x 10 is 30 and that 1.068 x 10000 is 10680

30

______

10680

= 0.00289575289 N

Low and behold.. not the right answer. It is the second time I got this same answer though so at least that's something, I suppose.

I'd really appreciate it if, even something that would inevitably cause me to get the wrong answer happened very early on, you'd tell me if there were other silly things I did with the numbers later.

Thank you!