Dimensional Analysis/Conversions

Warm-up (9/24/15) Please put stow your bags and your electronic devices. Quietly read the directions and begin working on the warm-up problems you picked up on your way in.

How many seconds are in a year? Think about the question above. (1 minute) Brainstorm how you might solve this problem if all you have is a piece of paper, a pencil, and a calculator. Write down any ideas on the back of your warm-up. Talk to your partner and discuss your ideas. Try to solve the problem using the ideas you discussed (2-3 minutes) We will come back to this problem again at the end of this presentation.

What is Dimensional Analysis?

What is the point of learning dimensional analysis? Dimensional analysis is something that we do everyday, many times on a small scale without even realizing it. You want to buy a candy bar that is $1.25 but you only have quarters. How many quarters will you need to buy the candy bar? We will be doing a lot of dimensional analysis later on in the school year when we begin learning about stoichiometry. It is best to start slow and get a good understanding of the concepts now to make it easier for you later.

How to Solve a Dimensional Analysis Problem

Lets Try a Problem!

If Tim is 6.00 feet tall, how tall is he in centimeters?

Let’s try one more…

One gallon of milk is equal to how many milliliters of milk?

Lets go back to how many seconds are in a year. Now that we have tried some practice problems, look back at the initial problem. Reflect, was your method correct? If not, what do you need to change? Discuss with your partner the changes you would make if any, and solve the problem. Volunteer to come do the problem on the board?

After your notes, write 2-3 conversion factors of your own. Write 2 or 3 conversion factors that you can come up with that are not on your conversion sheet or something we already talked about today Be creative, there are so many options!

Lab Work Expectations Work quietly with your group (voices should be heard by group members, but not across the room) Work at the lab station you are assigned until directed to move to the next station. You will have 6 minutes at each lab station. Allow an opportunity for every group member to participate Stay on task (you should be working on/discussing the assignment at hand) Raise your hand if you have a question and wait patiently until I can get to your station