70,000,000,000 newton's

Rewrite in prefix notation.

Is the answer this 70n (nano) N (newtons)?

is the answer this 70n (nano) N (newtons)?

No - "nano" means 1 billionth. That is, 10^{-9} . You want the notation for billion: 10 ^{+9} . Here's a list of prefixes that will help you:

SI prefix - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/SI_prefix)

I suppose this is actually quite tricky when you first come to learn it. One way of remembering is that "small" prefixes often have -i or -o on the end, and big prefixes are normally -a, the only exception being kilo- (and hecto- but that is rarely used).

Hopefully that will help you get it round the right way :)