# Specific Charge sum

1. Oct 23, 2009

### bacardiancoke

Hi all,

I'm reading through a section of my course about specific charge and I cannot figure out how exactly the example sum has got the answer it displays.

It uses carbon 12 as the example so displays the sum as:

= 9.61305876 x 10-19
------------------------------------------
20.08529244 x 10-27

= 0.4786118 x 10-19+27

= 0.4786118 x 108

= 4.4786118 x 107 Coulombs / kg

How exactly does it become (-19+27) when my working out of the very same sum has it at -46?

Thanks

2. Oct 23, 2009

### Staff: Mentor

$$\frac{1}{10^n} = 10^{-n}$$

$$\frac{1}{10^{-n}} = 10^n$$

3. Oct 23, 2009

### bacardiancoke

Thanks jtbell.

Was funny in a way, as soon as I hit "post" the penny dropped