PHYS 201

1. PHYS 201 Instructor : Dr. Hla Class location: Walter 245 Class time: 12 – 1 pm (Mo, Tu, We, Fr) Equation Sheet You are allowed to bring an A4 size paper with your own notes (equations, some graph etc.) to the midterm and final exam. No equation will be given.

2. PHYS 201 Chapter 1 Power of Ten Units Unit Conversions Basic Trigonometry Graphical Analysis Vectors Vector Components

3. Prefixes • tera (T): 1012 1,000,000,000,000 • giga (G) : 109 1,000,000,000 • mega (M): 106 1,000,000 • kilo (k): 103 1,000 • centi (c): 10-2 1 / 100 • milli (m): 10-3 1 / 1,000 • micro (μ): 10-6 1 / 1,000,000 • nano (n): 10-9 1 / 1,000,000,000 • pico (p): 10-12 1 / 1,000,000,000,000

4. OU Atomic logo 30 nm

5. Basic Units SI CGS BE Length [L] meter (m) centimeter (cm) foot (ft) Mass [M] kilogram (kg) gram (g) slug (sl) Time [T] second (s) second (s) second (s) Dimensions All the other units are derived units. Example: Speed can be expressed with mph (miles per hour, or mi / h). It is the unit of length divided by time (L / T).

6. Unit Conversion • Can't mix units when adding or subtracting - Need to convert • 18 km + 5 mi is not 23 • Can always multiply by 1 • 1 km =1000 m 1 = (1 km/1000m) • Can cancel units algebraically

7. Unit Conversion 1 mi = 5280 ft 1 mi = 1.609 km 1 m = 3.281 ft • Example 1 • Convert 80 mi to km. • Example 2 • Convert 60 mi/h to km/s, and m/s. • Example 3 • Convert 60 mi/h to ft/s.

8. Unit Conversion • Example 4 • You are driving on R33 near Logan with a speed of 26.67 m/s. The speed limit there is 65 mph. Will you get a ticket because you are speeding? • Example 4 • You are driving on R33 near Logan with a speed of 26.67 m/s. The speed limit there is 65 mph. Will you get a ticket because you are speeding?

9. Unit Conversion • CLICKER! Example 5 Convert 1000. ft/min into meters per second. 1). 0.197 m/s 2). 5.08 m/s 3). 24.5 m/s 4). 54.7 m/s 5). 169 m/s 6). 1540 m/s 7). 18300 m/s

10. Convert 1000. ft/min into meters per second. 0.0847 m/s 0.197 m/s 5.08 m/s 24.5 m/s 54.7 m/s 169 m/s 1540 m/s 18300 m/s 1 mi = 5280 ft 1 mi = 1.609 km 1 m = 3.281 ft ANSWER!

11. Unit Conversion • CLICKER! Example 6 A bucket has a volume of 1560 cm3. What is its volume in m3? A bucket has a volume of 1560 cm3. What is its volume in m3? • 1.56x10-6 m3 • 1.56x10-4 m3 • 1.56x10-3 m3 • (4) 1.56x10-2 m3 • (5) 1.56x10-1 m3 • (6) 1.56 m3 • (7) 15.6 m3 • (8) 1.56x103 m3 • (9) 1.56x106 m3 • (10) 1.56x109 m3

12. A bucket has a volume of 1560 cm3. What is its volume in m3? (1) 1.56x10-6 m3 (2) 1.56x10-4 m3 (3) 1.56x10-3 m3 (4) 1.56x10-2 m3 (5) 1.56x10-1 m3 (6) 1.56 m3 (7) 15.6 m3 (8) 1.56x103 m3 (9) 1.56x106 m3 (0) 1.56x109 m3 ANSWER! 1560cm3 = 1560 cm*cm*cm(1m/100cm)*(1m/100cm)*(1m/100cm) = 1.56x10-3 m3 How do you interpret cm-3 ? Negative exponent – inverse – place in denominator

13. Trigonometry • Right Triangle Sum of angles = 180 opposite angle = 90-θ

14. Trigonometry • Right Triangle

15. Which is true? A = B + C B = A – C C = A + B CLICKER! 2 2 2 C 2 2 2 B 2 2 2 q A

16. Which is true? A = C sin q A = C cos q B = C cos q CLICKER! C B q A

17. Example: You walk a distance of 20m up to the top of a hill at an incline of 30°. What is the height of the hill? Note: DRAW PICTURE! 20m h 30º

18. What is the angle θ?

19. DIMENSIONS Length: L Mass: M Time: T Examples: 1). Speed: unit (mi/h). Dimension: [L/T] 2). Area : unit (ft2). Dimension: [L2] 3). Acceleration: Unit (m/s2). Dimension: [L/T2] 4). Force: Unit (kg. m/s2) . Dimension: [ML/T2]

20. DIMENSIONS Length: L Mass: M Time: T Dimensions of left and right side of an equation must be the same. Example: x = ½ vt2 L = (L/T) (T2) = LT [Dimensions at left and right are not the same. WRONG equation.] Example: x = ½ vt L = (L/T) (T) = L [Dimensions at left and right are the same. CORRECT equation.]

21. You are examining two circles. Circle 2 has a radius 1.7 times bigger than circle 1. What is the ratio of the areas? Express this as the value of the fraction A2/A1. (1) 1/1.7 (2) 1.7 (3) (1/1.7)2 (4) 1.72 (5) (6) Example: CLICKER! 2 1

22. Slope of Function on Graph Slope = rise/run Up to right is positive Slope of curve at a point slope of tangent line Slope of straight line same at any point y rise = Δy run = Δx x y A x

23. The slope at point B on this curve is _________ as you move to the right on the graph. increasing decreasing staying the same CLICKER! y B x

24. The slope at point B on this curve is _________ as you move to the right on the graph. increasing decreasing staying the same B y CLICKER! x

25. The slope at point B on this curve is _________ as you move to the right on the graph. increasing decreasing staying the same y B x

26. Vectors

27. Vectors Direction length = magnitude Some VECTOR quantities -Displacement (m, ft, mi, km) -Velocity (m/s, ft/s, mi/h, km/hr) - Acceleration (m/s2, ft/s2) -Force (Newton, N)

28. Vector Summation A B C + = C A B + =

29. Vector Summation C = A + B A + B Two ways to sum the vectors: Parallelogram method (1), and triangle method (2). 1) 2)

30. Vector Summation C B 2 2 C = A + B q B -1 A = tan q A

31. Which is true? CLICKER! C = A + B 1) 2) A 3) B 4)

32. Which is true? CLICKER! C = A + B 1) 2) A B 3) 4)

33. Vector Component Y A A Y q x A x

34. Example 30 N o 40 N 60 An object is pulled by strings with 30 N and 40 N forces respectively as shown. Find (a) the magnitude of the net force. (b) the direction of the net force (find the angle).

35. CAPA • -Round up the numbers (e.g. 3.247321 3.25) • Add the units: (e.g. cm, N (newton), deg (degree)) • Do not forget to put ‘-’ sign in vectors if the resultant vector is in –x or –y direction. • For m/s2 m/s^2