## Exercise 8.7

$\Delta U=q+w$

Kellina Tran 2I
Posts: 50
Joined: Sat Jul 22, 2017 3:00 am

### Exercise 8.7

Why is it that the answer is written as +4.90 x 10^2 J instead of kept as 490 J?

Hyein Cha 2I
Posts: 103
Joined: Fri Sep 29, 2017 7:05 am
Been upvoted: 1 time

### Re: Exercise 8.7

it's just to keep track of sig figs. You do not need to write it in scientific notation :)

Katelyn 2E
Posts: 35
Joined: Sat Jul 22, 2017 3:01 am

### Re: Exercise 8.7

My TA said that sig figs aren't as big a deal this quarter because students end up focusing more on worrying about sig figs than they do about getting the actual concepts down/the problems right. But yes, answer is written in scientific notation just for the purpose of sig figs.