# Monthly Archives: August 2012

# Hon Chemistry 8-29-12 Scientific Notation

HON CHEMISTRY – Wow – that might be the fastest I’ve reviewed scientific notation ever! Here’s the lecture from Wednesday. Are you ready to kill your calculator yet? The best way to really learn all of the things from this chapter is practice, practice, practice! And just so you can do that, I’ve put it all together in your homework tonight….cuz I love you! π You can do it!!

# Chemistry 8-29-12 Accuracy & Precision

CHEMISTRY – Hey guys, here’s the super fast lecture from Wednesday on accuracy, precision and percent error. Keep that formula for percent error handy, you’ll be using it all year! We’ll finish discussing significant figures tomorrow. You’ve made a great start on learning to measure with sig figs (we did that during the unit on lab stuff!), so now let’s crank it up a notch and begin to calculate with them. Don’t panic about the homework, I’ll show you tomorrow! (Just make sure you try it!!)

P.S. Are you ready for the SI quiz tomorrow? Don’t forget to study SI prefixes and their meanings, SI quantities and their symbols, and the SI units used to measure those quantities. Be proactive in your studying. For heaven’s sake, don’t just read the list – ake flashcards, use quizlet.com, get someone to call them out to you! Good luck!

# Physics 8-28-12 … and the Tortoise & the Hare

PHYSICS: Just in case you need it, here is the solution to the tortoise and the hare problems – # 21 & 22. Remember a few things: You weren’t born knowing how to do these – give yourself a little time. Just one formula won’t work – begin with writing what your know. These are some of the hardest problems we’ll work in physics – not because the formulas are hard, but because knowing how to reason through them is so challenging. You are doing a great job! BYW – Don’t open the solutions you wrote in your notes! Try it without it!!

Tomorrow I’ll give you a break – we’ll work with the Sparkvue labs again. Thanks for helping get them set up!

# Hon Chemistry 8-28-12 Conversion Factors

HON CHEMISTRY – Hey guys! So how fast would this be in Guatemala? Did you feel like you were in a foreign language class today? Good job on using conversion factors! I know you’ve worked these problems in your math courses, make sure you learn to work them using the Q formula!!

# Chemistry 8-28-12 SI Density Problems

CHEMISTRY – So you thought Goodman Road was getting crowded! How’s this for a “high density” city? Great job on the density problems today! Remember, in chemistry we use math as a tool, therefore we might work problems a little differently in chemistry than you do in your math class.

When working these problems, don’t forget to follow the problem solving steps we discussed today. Analyze – write down what you’re given and what you’re looking for, plan – write a formula where you isolate the unknown on one side by itself, compute – plug in your data, numbers and units. Then cancel the units, and if they cancel correctly, go on to the calculator. Be sure and give your answer what the correct units. And finally, evaluate – does your answer make sense, have you used the correct units, do you have the correct sig figs? Wait – scratch that last thing, we’ll do sig figs in a couple of days.

And who knew raisins could dance! I think you’ve done a lot of this already, but make sure you understand the conceptual side of density as well – that’s a hint for your conclusion!

π

# Physics 8-27-12 Velocity Problems 2

PHYSICS – Velocity problems from Monday – you did a great job on these! Now let’s see what you can do on your own! r you.

Good luck on those five problems. No peeking! Try not to look at your notes, but if you do, work it again without your notes! And make sure to do more than just show the math – be sure that I can also follow your logic in the formulas. Ditto with units, etc. Don’t give up on the tortoise and the hare. A couple of hints: remember the distance the tortoise travels is the same as the distance the hare travels plus the extra 20 cm he was ahead. Also, the time the hare raced is equal to the time of the tortoise minus those two minutes he rested. Now go have fun! π

# Chemistry 8-27-12 SI Measurement, Pt. 2

CHEMISTRY – Hey guys, here’s another picture of those “high density” koi that I was telling you about in class today. I saw then when I got to visit my brother in Hawaii, at the Dole Pineapple Plantation, of all places!

So do you feel comfortable with the fundamental and derived units/formulas that we’ve discussed? Here’s the lecture from Monday. Be sure and practice the density problems and we’ll double check them tomorrow. Speaking of tomorrow, can you apply what you know about density?

On a more practical side, how is your balance coming? Have you figured out how density plays a major part in how it works? Here are the actual masses. Are your answers close to these? If not, what could be some reasons? Make sure you include that in your conclusion. Holler if you have any questions! π

β’ Penny: 3.10 g before 1982, 2.50 g after

β’ Nickel: 4.95 g

β’ Dime: 2.25 g

β’ New state quarter: 5.68 g

# Hon Chemistry 8-27-12 Accuracy, Precision, & Intro to Significant Figures

HON CHEMISTRY – So which is more important, accuracy or precision? Good question! Here’s the lecture from Monday on just that. Don’t lose that percent error formula – you’ll use it all year!

And then, drum roll please, just what you’ve been waiting for – your first intro into significant figures! Go on, be happy!!

# Hon Chemistry 8-24-12 Derived Units

HONORS CHEMISTRY – Hey guys, here’s a pic of high density koi that I saw in Hawaii (at the Dole Pineapple Plantation, of all places!).

So do you feel comfortable with the derived units/formulas that we discussed? Here’s the lecture from Friday. Be sure and practice the density problems and let me know Monday how you’re doing with them.

On a more practical side, how is your balance coming? Have you figured out how density plays a major part in how it works? Here are the actual masses. Are your answers close to these? If not, what could be some reasons? Make sure you include that in your conclusion. Holler if you have any questions! π

β’ Penny: 3.1 g before 1982, 2.5 g after

β’ Nickel: 4.95 g

β’ Dime: 2.25 g

β’ New state quarter: 5.68 g