1. Do Now & Announcements Take out HW to be checked Work on warm up problems Dimensional Analysis Quiz (Short) ◦ Thurs 9/4 ◦ Friday 9/5 If you need help with the Dimensional Analysis questions, come by Mustang Morning!

2. x10 x1000

3. Telephone 602,000,000,000,000,000,000,000 6.02 x 10 23

4. Scientific Notation Scientific notation is used to express very large or ­very small numbers more easily. It is written as a (decimal between 1 & 10) x 10 raised to an exponent

5. How to express a number in terms of scientific notation: 1. Move the decimal point of your number so that you have a decimal between 1 and 10

6. How to express a number in terms of scientific notation: 2. Count the number of spaces (n) and which direction you moved the decimal point

7. How to express a number in terms of scientific notation: 3. If you moved the decimal point to the left multiply (x) your decimal by 10 n 360,000  3.6 x 10 5 If you moved the decimal point to the right, multiply (x) your decimal by 10 —n 0.00037  3.7 x 10 —4

8. Practice Write the following numbers in terms of scientific notation 1) 198,000,000 __________________ 2) 0.000023 ___________________ 3) 7200 ___________________ 4) 0.0000047 ___________________

9. How to express a value given in scientific notation as a normal number: 1. Identify the exponent 3.6 x 10 5 : exponent 5 3.7 x 10 —4 : exponent –4

10. How to express a value given in scientific notation as a normal number: 2. If the exponent is a positive number, move the decimal point the same number of places to the right 3.6 x 10 5 : move decimal 5 places to the right

11. How to express a value given in scientific notation as a normal number: 3. If the exponent is a negative number, move the decimal point the same number of places to the left. 3.7 x 10 —4 : move decimal 4 places to the left

12. Practice Write the following scientific notation expressions as a normal number 1) 9.3 x 10 7 ____________________ 2) 1.7 x 10 —4 ____________________ 3) 1.03 x 10 —3 ____________________ 4) 3.937 x 10 5 ____________________

13. Dimensional Analysis Continued: Non SI- SI conversions: MULTIPLE STEPS! Ex 1: Let’s revisit the problem: How many breaths do you think you take in a lifetime? Let’s start with how many breaths you take in 1 minute ______________________

14. Dimensional Analysis Continued: Non SI- SI conversions: MULTIPLE STEPS! Ex 2: Measure the number of beats your heart makes in 30 seconds __________________ Determine your cardiac output in mL of blood per minute. Assume your heart pumps 70 mL of blood per beat (this is known as the stroke volume). Assume your body contains 5 L of blood. How long does it take in minutes to pump all of your blood around your body once?

15. Dimensional Analysis Continued: Non SI- SI conversions: MULTIPLE STEPS! Ex 3: You’re traveling from the US to Europe to China. You have $1000 (US currency) left over in the form of Euros. You take these Euros to exchange them for RMB when you land in China. How much money in RMB should you expect to receive? Assume $1 US = 0.76 Euros and 1 Euro = 8.12 RMB.

16. Reading Graduated Cylinders: ◦ Liquids form a curved surface when in graduated cylinders. As a standard, you should read the liquid level from the bottom of the meniscus

17. Unit Conversion Activity Use Dimensional Analysis to complete the task at each station Express your answer using normal notation AND scientific notation

18. Accuracy vs. Precision Accuracy=how close the results are to the correct answer (Bull’s eye!) ◦ To determine accuracy, we look at the average of our results. Precision= how often the same results are measured/obtained ◦ To determine precision, we look at the consistency of our results.

20. AVERAGE ACCURATE NO

21. each trial/measurement precise NO

22. Accuracy vs. Precision Practice YES

23. Accuracy vs. Precision Practice YES NO YES 99 4.67