Do Now & Announcements Take out HW to be checkedWork on warm up problemsDimensional Analysis Quiz

(Short)◦Thurs 9/4◦Friday 9/5

If you need help with the Dimensional Analysis questions, come by Mustang Morning!

x10

x10x10

x10

x10x10

x1000

x1000

x1000

Telephone602,000,000,000,000,000,000,00

0

6.02 x 1023

Scientific NotationScientific 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

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

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

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 10n

360,000 3.6 x 105

If you moved the decimal point to the right, multiply (x) your decimal by 10—n

0.00037 3.7 x 10—4

Practice

Write the following numbers in terms of scientific notation1) 198,000,000 __________________2) 0.000023 ___________________3) 7200 ___________________4) 0.0000047 ___________________

How to express a value given in scientific notation as a normal number:

1. Identify the exponent 3.6 x 105: exponent 5

3.7 x 10—4: exponent –4

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 right3.6 x 105: move decimal 5 places

to the right

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

Practice

Write the following scientific notation expressions as a normal number1) 9.3 x 107 ____________________2) 1.7 x 10—4 ____________________3) 1.03 x 10—3 ____________________4) 3.937 x 105 ____________________

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 ______________________

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?

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.

 

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

Unit Conversion ActivityUse Dimensional Analysis to

complete the task at each stationExpress your answer using

normal notation AND scientific notation

Accuracy vs. PrecisionAccuracy=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.

AVERAGE

ACCURATE

NO

each trial/measurement

precise

NO

Accuracy vs. Precision Practice

YES

YES

Accuracy vs. Precision Practice

YES

NO

NO

YES99

4.67