# Physics 8-31-11 Acceleration

PHYSICS: Great intro to acceleration! How do you feel about the formulas you helped me to derive? Go ahead and start the homework, and we’ll finish the last formula tomorrow – yes, there’s just one more. I think you’ll come to find these are a ton better than some of the velocity problems you did. List what you are given and what you’re looking for – don’t forget things like “starts from rest” and “came to a stop.” Then, just find the formula that contains the variables you are looking for. Easy peazy! Okay, maybe not that easy! π

# Hon Chemistry 8-31-11 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 8-31-11 Significant Figures

CHEMISTRY – Great job on using sig figs today! Here’s the lecture from Wednesday on identifying significant figures and using them in calculations. Don’t forget to keep practicing! And speaking of practice….Help Session, Friday morning at 7:15. π

# Chemistry 8-30-11 Accuracy & Precision

CHEMISTRY – New – with sound!!

Hey guys, here’s the lecture from Tuesday 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, 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!!)

# Hon Chemistry 8-30-11 Significant Figures

HON CHEMISTRY – Wow! Learned some Greek today, huh? Sig figs may seem a little confusing to begin with, but they are extremely important to learn for the rest of the year. Here’s the lecture from Tuesday on using sig figs in measuring and calculations. Do you need some practice? And how are you doing on memorizing the SI prefixes and units? Let’s put it all to good use tomorrow! π

# Physics 8-29-11 … 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 solution to number 7! Try it without it!!

Tomorrow I’ll give you a break – we’ll start acceleration. I think you’ll find that it’s a whole lot simpler – all you have to do is practice using some formulas! Did you hear what I said? Formulas!! π Not simple mind you, but you’ll be surprised how much you’ve already learned. I’m proud of you!!

# Hon Chemistry 8-29-11 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 (the upload acted a little hinky – holler if it won’t open). 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!!

# Physics 8-26-11 Velocity Problems 2

PHYSICS – Velocity problems from Thursday – you’re doing a great job on these! Let me know how the take home lab is going for you. I think it will be a good break from your typical type of homework!

Good luck on those five problems. 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 8-26-11 SI Derived Units

CHEMISTRY – So you thought Goodman Road was getting crowded! How’s this for a “high density” city? Here’s the lecture from Friday on derived SI units. 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. I think you’ve done a lot of this already, but make sure you understand the conceptual side of density as well!

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. You’ll just have to wait! π

# Physics 8-25-11 Velocity Problems

PHYSICS: Hey guys, here’s the work we did on the homework from Tuesday night, especially number 11. π So can you work it by yourself now? Don’t just copy your notes! Soooooooo…. did we work it right in class? Come on, you can do it – and let’s crank it up a notch tomorrow!

flickr photo by darkmatter