Measurements in Physics

1. Measurements in Physics Standard Units Standard Prefixes Conversions

2. Some obnoxious values • My laptop has a memory capacity of • 119,768,268,800 bytes • The fastest computer in the world has a processing speed of • 128,125,110,000 operations per second (flops) • The average camera has a resolution of • 3,212,412 pixels • The mass of the Sun is approximately • 19,891,675,400,000,000,000,000,000,000 kg

3. Obnoxious Values • Could you imagine if every computer ad had to provide memory storage in bytes? • What if cameras had labels showing their exact resolution? • What if astronomy textbooks had to print the full mass of the Sun every time?

4. Obnoxious Values • To remedy this, physicists have two solutions • Scientific notation • Greek prefixes • I will assume that you know how to write numbers in scientific notation, so we will focus on the Greek prefixes today

5. Greek Prefixes

6. Some simple conversions • 10 rations • 2000 mockingbirds • 10-6 phones • 1018 miners • 10-12 boo • 109 low • 10-18 boy • 106 phones • 2 x 1012 bull

7. 10 rations 2000 mockingbirds 10-6 phones 1018 miners 10-12 boo 109 low 10-18 boy 106 phones 2 x 1012 bull 1 dekarations 2 kilomockingbird 1 microphone 1 examiners 1 picaboo 1 gigolow 1 attoboy 1 megaphone 2 terabull Some simple conversions

8. Converting between units • Often in physics we need to convert between various units • Convert the given value to the desired units

9. 234 nm = ____ m Problem 1

10. 0.012 μg = ____ g Problem 2

11. 9.6 km = ___ m = ___ cm Problems 3 and 4

12. 1042500 sec = ____ min = ____ hrs = ___ days Problems 5, 6 and 7

13. 9600 mm = ___ cm = ___ km Problems 8 and 9

14. 5 m/s = ____ km/hr Problem 10