Physics Topics I. MECHANICSMECHANICS II. WAVES AND OPTICSWAVES AND OPTICS III. ELECTRICITY AND MAGNETISMELECTRICITY AND MAGNETISM IV. MODERN PHYSICSMODERN PHYSICS V. ASTRONOMYASTRONOMY

Thinking Back… What were some of the tools of a Physicist?

Thinking Back… What were some of the tools of a Physicist? Practice safety & ethics Identify & describe equipment Use SI System Manipulate formulas The Scientific Method Use Lab Report Format

What do you know? What is a frame of reference?

What do you know? What is a frame of reference? A system to determine location or motion of an object. How can I tell if something is moving and how fast?

What is acceleration?

Rate of change of speed Occurs when we fall or go around a corner

What are forces and how do they commonly occur?

A force is a push or a pull They commonly occur in pairs

What are Newton’s Laws of Motion?

#1 Inertia #2 F = ma #3 Action/Reaction

Motion I Motion in One Dimension - Quantities, Units, Speed, Position, Distance, Displacement, Velocity, Vector, Scalar, etc.

Assignment Read Chapter 2 After reading the chapter, complete your Reflections on the chapter.

What you need to know ¤Motion can be described and analyzed in several ways ¤How coordinate systems can be used in motion studies ¤Terms such as displacement, magnitude, vectors ¤More Terms: scalars, resultant vectors ¤Interpret motion graphs ¤Attributes of coordinate system - origin & axis ¤Models of motion diagrams

Also Needed to Know ¤Speed, distance (d), and time are scalar quantities. ¤Velocity, displacement (s), force and acceleration are vectors. ¤The slope of the distance-time graph is velocity. ¤The slope of the velocity-time graph is acceleration.

possibilities Object not moving, v = 0 m/s Object moving at constant velocity Object accelerating Object decelerating (negative acceleration) (Last 2 situations have unbalanced forces acting on them - to be discussed later in the book)

Organizing your thoughts (and units) Fundamental Quantities –Length –Mass –Time Derived Quantities –Velocity –Density –Volume Fundamental Units –Meter –Kg –Sec Derived Units –m/s –g/ml or g/cm 3 –m 3 or cm 3

The "Big Five" Kinematics Equations Constant acceleration is assumed Average Speed/Velocity Defined v = d / t = ½(V f + V o ) Average Acceleration Defineda = ∆v / ∆t = (V f - V o ) / (t f - t o ) Final Velocity of an Accelerating Body V f = V o + a(∆t) Distance Traveled by an Accelerating Body d = V o (∆t) + ½ a(∆t) 2 What can I do if I don't know the time interval? V f 2 - V o 2 = 2 a d

In the above formulas, a can be replaced with g g = 9.8 m/s  (acceleration on Earth due to gravity when an object is falling) Equation of motion for average velocity: d = vt + d i

Online Notes 2.htmlhttp:// 2.html This site has information which may be helpful to you in your basic study of Physics.

Scalars & Vectors Scalars have magnitude only (a number with units) such as a length of 5.0 m or a speed of 29.3 m/s Vectors have magnitude and direction –Velocity: 29.3 m/s North –Force: 25 newtons South –Displacement

Vectors Are represented by an arrow Length drawn to a chosen scale (1cm:50m/s) Direction N S E W Vector addition: –Same direction: add –Opposite directions: subtract

Adding Vectors ABRABR A B R A + (-B)  R A + B  R