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.

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

Prefixes tera (T): ,000,000,000,000 giga (G) : ,000,000,000 mega (M): ,000,000 kilo (k): ,000 centi (c): / 100 milli (m): / 1,000 micro (μ): / 1,000,000 nano (n): / 1,000,000,000 pico (p): / 1,000,000,000,000

OU Atomic logo 30 nm

Basic Units SICGSBE 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).

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

Unit Conversion 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. 1 mi = 5280 ft 1 mi = km 1 m = ft

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

Unit Conversion Example 5 CLICKER! Convert ft/min into meters per second. 1) m/s 2) m/s 3) m/s 4) m/s 5). 169 m/s 6) m/s 7) m/s

Convert ft/min into meters per second m/s m/s m/s m/s m/s m/s m/s m/s 1 mi = 5280 ft 1 mi = km 1 m = ft ANSWER!

Unit Conversion Example 6 CLICKER! (1)1.56x10 -6 m 3 (2)1.56x10 -4 m 3 (3)1.56x10 -3 m 3 (4) 1.56x10 -2 m 3 (5) 1.56x10 -1 m 3 (6) 1.56 m 3 (7) 15.6 m 3 (8) 1.56x10 3 m 3 (9) 1.56x10 6 m 3 (10) 1.56x10 9 m 3 A bucket has a volume of 1560 cm 3. What is its volume in m 3 ?

(1) 1.56x10 -6 m 3 (2) 1.56x10 -4 m 3 (3) 1.56x10 -3 m 3 (4) 1.56x10 -2 m 3 (5) 1.56x10 -1 m 3 (6) 1.56 m 3 (7) 15.6 m 3 (8) 1.56x10 3 m 3 (9) 1.56x10 6 m 3 (0) 1.56x10 9 m cm 3 = 1560 cm*cm*cm (1m/100cm)*(1m/100cm)*(1m/100cm) = 1.56x10 -3 m 3 How do you interpret cm -3 ? Negative exponent – inverse – place in denominator ANSWER!

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

Trigonometry Right Triangle

Which is true? 1.A = B + C 2.B = A – C 3.C = A + B B CLICKER! A C 

Which is true? 1.A = C sin  2.A = C cos  3.B = C cos  B CLICKER! A C 

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! 30º 20m h

What is the angle θ?

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

DIMENSIONS Length: L Mass: M Time: T Dimensions of left and right side of an equation must be the same. Example: x = ½ vt 2 L = (L/T) (T 2 ) = 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.]

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 A 2 /A 1. (1) 1/1.7(2) 1.7(3) (1/1.7) 2 (4) (5) (6) Example: 1 2 CLICKER!

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 x y run = Δx rise = Δy x y A

The slope at point B on this curve is _________ as you move to the right on the graph. 1.increasing 2.decreasing 3.staying the same x y B CLICKER!

The slope at point B on this curve is _________ as you move to the right on the graph. 1.increasing 2.decreasing 3.staying the same x y B CLICKER!

The slope at point B on this curve is _________ as you move to the right on the graph. 1.increasing 2.decreasing 3.staying the same x y B

Vectors

Direction length = magnitude Some VECTOR quantities -Displacement (m, ft, mi, km) -Velocity (m/s, ft/s, mi/h, km/hr) - Acceleration (m/s 2, ft/s 2 ) -Force (Newton, N)

Vector Summation += ABC += AB C

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

Vector Summation A B C  C = A + B 22  = tan A B

Which is true? CLICKER! A B ABC =+ 1) 2) 3) 4)

Which is true? CLICKER! A B ABC =+ 1) 2) 3) 4)

Vector Component A A A Y x  x Y

Example 40 N 30 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).

CAPA - Round up the numbers (e.g ) -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/s 2 m/s^2