serious help people? PHysics and math people!?

Question

ok.. i took a test and did this:
8.55 x 10^10 ng X 1g / 10^-9 ng = 8.5 x 10^19

she marked it wrong and put that it was suppose to be 10^positive 9 ????? but why????? isn't the scientific notation for n 10^-9?????

n nano

if you don't get wut im saying let me kno and i give you another problem where she did that....


yeah , i have a re-take tomorrow and i need help

Answer 1

One gram is 10^9 nanograms, 10^10 ng is 10 g so the upper part is 85.5 g = 8.5 x 10 g.
10^-9 ng is 10^-18 g so 8.5 x 10 / 10^-18 = 8.5 x 10^19
There is probably a typo.

Answer 2

The sign is incorrect. Think of it this way, think of that '/' as meaning "per". so you are multiplying by 1g per 10^-9 ng. But it should be 1g per 10^9 ng. In other words, a billion ng in a gram.

This is how I think of it anyway.

Double check by thinking of what you're trying to do. If you have a bunch of ng, the number of g is going to be smaller, not bigger.

Answer 3

I don't follow the line of math you put up. But I think from your text that you are converting from grams to nanograms?

1 gram = 10^9 nanograms

Nanograms are small - if the units get smaller, the digits need to get bigger to keep the same value. If you have 6 dollars, that's the same as 600 pennies. Right?

Answer 4

whats ng? And, just ask the teacher what you did wrong, play the sympathy card.