What is Physics?

1. What is Physics? Describes everything around us using a few basic concepts, equations, and assumptions. Includes any problem that deals with temperature, size, motion, position, shape, or color. Major areas: Mechanics = motion; thermodynamics = heat and temperature; Wave phenomena = vibration & sound; optics = light; electromagnetism = duh; relativity = moving particles/objects at any speed including high speed

2. Math and Measurements -All the stuff before we get to the real physics

3. Measurement We will use the… • SI (Systeme International) There are 7 Basic units from which all others are derived:

4. For now, we will only focus on… ____________, ___________, ___________ So, what are the English equivalents of these measurements?

5. The $125 million mistake In 1999, the Mars Climate orbiter burned up in Mars’ atmosphere because of a mistake with units. It was discovered that one team was using English units (feet, pounds, etc) while the other was using metric units when performing a maneuver to put the spacecraft into orbit about Mars.

6. ________________ Scientific Notation Used as a way to simplify the writing of very large and very small numbers. 500 0.005 ________________ 456, 234 ________________ 0.000827 ________________

7. Orders of Magnitude Used as an easy way to compare numbers 10 = 101= _______ 100 = 102= ______ 1000 = 103= ______ 5.0 x 104 is about ________ larger than 4.5 x 102 OR It is ______________ larger - way of estimating sizes

8. No Measurement is Perfect! Two factors are used to describe the imperfection: Accuracy= how close a measurement is to the accepted value Precision=the degree of exactness of a measurement Confidence intervals or limits are used to show the degree of uncertainty. Ex: 45.3 ± 0.8 or 45.3 ± 0.1 Which is more precise?

9. 16.3cm 4.5cm Significant Figures Tells us accuracy of measurements made • Find the area of the box with correct significant figures. Answer can only have the number of S.F as your _____________ __________ when multiplying or dividing terms.

10. Other Rules When added or subtracted, the number of decimal places in the result should equal the smallest number of decimal places of any term in the sum. 25.32 g + 10.2 g _____ g

11. Zeros – Zeroes that are used only to position the decimal point are not significant. ex. 1300 1300. 1.0 x 10-7 0.0013 0.00130 1302 13.020 Remember the Atlantic/Pacific Rule?

12. How many sig figs are in the following: 1.30 x 104 0.00134 1.001340 1.0 x 105 Do the following calculations to the correct number of sig figs. 2.02 x 5.0 1,250 x 1,000 4.501 x 10.6 154 x 33.4

13. Powers of 10

14. Applying prefixes to meters we get: 1 μm = 10-6 m 1 mm = 10-3 m 1 cm = 10-2 m 1 km = 103 m 1 m = 106 μm 1 m = 103 mm 1 m = 102 cm 1 m = 10-3 km Both tables represent the SAME information

15. Unit Conversions Ex. Convert 3 days into seconds. Ex. Convert 18 km into centimeters.

16. Approximating Sizes The length of the room is approximately: 15 mm 15 cm 15 m 15 km The mass of a physics textbook is approx: 103 kg 101 kg 100 kg 10-2 kg

17. Graphing x-axis : independent variable (thing you are changing) y-axis : dependent variable (thing you are measuring or seeing if it changes) scale : make sure each line on the graph paper represents the same increment (ex. 1 kg or 2 cm) and fills the page Labels : make sure that each axis has an appropriate label and units.

18. In an experiment you measure the effect of changing the mass hung from a spring to the distance the spring stretches. You record the following data • Graph the following data • include a line of best fit (trend line) • find the slope of the line.

19. As a motorcycle starts from rest, you measure the distance it has traveled (in meters) after each second. • Graph the effect of distance vs. time • Include a line of best fit.