## Wednesday, November 10, 2010

### Review #30

Just making sure we covered everything, I chose Dimensional Analysis because we covered it so early some of us may have forgotten it by now. Here are some questions you can try out and the answers are listed at the bottom.

Here are the conversions you will need:
1 miles= 5280 ft.

1 inch= 2.54 cm.
1 lightyear= 9.467x10^15m
1 parsec= 1.91738x10^13 mi.

1) 5.0 in = __ mm
2) 123.0 ng= __ Mg
3) How many parsecs make up a lightyear?

Key:
1) 127
5in. x 2.54cm/1 in. x 1m/100cm x 1000mm/1m

2)1.230x10^-13
123.0ng x 1g/10^9ng x 10^-6Mg/1g

3) 0.3068
9.467x10^15m x 100cm/1m x 1in./2.54cm. x 1ft./12in. x 1mi./5280ft. x 1 parsec/1.91738x10^13

1. Dimensional Analysis was a great topic to review, and you provided good examples. Another thing that may be useful is to know some important conversions. For many of the dimensional analysis problems, you need to recall conversions. Here are a couple important ones:
10^-9 m = 1 nm
10^-6 L = 1 muL
1 L = 1000 cm3
1 mL = 1 cm3
1 J = 0.2390 cal
1 cal = 4.184 J
1 Cal = 1000 cal (or 1 kilo calorie)

2. God job Madison! i agree with Christina. i would have covered the conversions that we need to have memorized for the exam. I like the examples, but they are a little confusing. i used equation editor to organize mine, and i found it helpful. overall you did am amazing job!

3. another good topic to cover might have been lad safety because that was the first thing we did and I think it would be really helpful to review before the exam.

4. Good job Madison! I totally forgot about dimensional analysis. I also forgot about lightyears but at least we don't have to memorize them! Good luck on your exam!