Chapter 1-3 Outline

Chapter 1 Introduction, Measurement, Estimating

Two branches of Physics: ClassicalModern Motion (Mechanics), Fluids, Head, Sound, Light, Electricity and Magnetism Relativity, Matter, Nuclear, Particles

1-1 Nature of Science Observations –Includes designing and carrying out experiments –Often have to use your imagination, as not every detail is always observed Theories –These are the other half of scientific process –Often derive from observations –Are formed and corrected through observations and experiments Testing –Theories can be tested and supported, but they are never “proven” –This is due to an inexactness of measurement and lack of ability to test every possible theory, thus theories often change over time –Theories which are more general and explain more are accepted –The simpler theory is accepted

1-2 Physics and its Relation to Other fields Physics has evolved from philosophy; physics is involved in most sciences

1-3 Models, Theories, and Laws Model –analogy or imagery to explain phenomena Theory –broader than a model (also testable) Principle/Law –Laws are principles that have been found to be true in many cases

1-4 Measurement and Uncertainty: Significant Figures Precision = consistency; Accuracy = correctness Significant figures = non-zero numbers Scientific Notation = M x 10 n

1-5 Units, Standards, and the SI System Measurements need units Units need a standard, which defines what the unit is Length = m, Time = s, Mass = kg There are 7 base units: m, s, kg, A, K, mol, cd (we don’t use candela)

1-6 Converting Units Use factor-label

1-7 Order of Magnitude: Rapid Estimating This is how I want you to estimate answers to see if they are reasonable (using Sci Not)

1-8 Dimensional Analysis Very important! Can help you determine what the equation should be

Chapter 2 Describing Motion: Kinematics in One Dimension

Chapter 2: 1-D Kinematics Mechanics = the study of the motion of objects (force and energy) –Kinematics-HOW objects move –Dynamics-WHY objects move Translational Motion = motion without rotation Particle Model = we are only concerned how the object would move if it were a particle (i.e., it cannot rotate)

2-1 Reference Frames and Displacement Reference frame = what the motion is relative to Coordinate axis = same as in math class Position = displacement from origin Displacement = distance that has a direction and is relative to its starting point

2-2 through 2-4: Speed, Velocity, and Acceleration Speed is the rate at which you travel Average speed is the change in distance over the change in time Velocity is speed with a direction Average velocity is displacement over time Instantaneous velocity is the velocity as the time interval approaches zero (infinitesimally small) Acceleration is the rate at which the velocity changes

2-5 Constant Acceleration Leads to the Kinematics equations We use x for distance/position/displacement (technically position)

2-6 Solving Problems Demonstrate #14, 15, 20, 30, 31 (Final three students will try on their own)

2-7 Falling Objects All fall at the same rate, 10 m/s2

2-8 Graphical Analysis of Linear Motion Same rules that we learned last year (slope of x- t is v, curvature is a; slope of v-t is a, area is displacement) This year we will include acceleration-time graphs (a-t graph is the slope of the v-t graph, area under an a-t graph is the change in velocity) Also, all graphs must be rounded off when changing between regions-you may not have a region that has an infinite slope or dotted lines

Practice Problems Problems: Pages Demonstrate: #14, 15, 20, 30, and 31 Homework: Problems 21, 25, 39 (window in helicopter), 56, 84, and 85

Chapter 3 Kinematics in Two Dimensions; Vectors

Chapter 3: Kinematics in 2-D; Vectors Projectile Motion: Objects projected outward near the surface of the Earth Vectors are needed to use as a tool

3-1 Vectors and Scalars Vector = has magnitude and direction Scalar = no direction associated with them Magnitude is represented by length, direction tip Vectors are bold in the text

3-2 Addition of Vectors-Graphical Methods If vectors are collinear, you may add them algebraically (one direction positive, opposite negative) If vectors are at angles to one another, must use another method Resultant is the net result when adding (multiplying) vectors Tail-to-tip method is a way to add vectors

3-3 Subtraction of Vectors and Multiplication of a Vector by a Scalar Subtracting is like adding a negative To make a vector “negative,” reverse the direction When multiplying by a scalar, change the magnitude of the vector only

3-4 Adding Vectors by Components Components = parts of a vector that, when added together, make the original vector Resolving = making a vector into its components We use the x, y, and z components –x = rcos  –y = rsin 

3-5 Projectile Motion Projectile Motion = motion in 2-D Motion in one direction is independent of motion in the other direction

3-6 Solving Problems Involving Projectile Motion Make an info box Modified kinematics equations xy d0d0 dfdf vovo vfvf a t

3-7 Projectile Motion is Parabolic Parametric Equations: x = v 0x t y = v 0y – ½ gt 2

3-8 Relative Velocity  Velocities may be changed from one reference frame to another if you know how fast the frames are moving relative to one another

Practice Problems Problems: Pages Demonstrate: #31 Homework: Problems #17, 18, 35, 30, and 41