Chapter 1; Section 1 Road Runner Video Notes:

Observing Motion Reference Point: Object that appears to stay in place Ex: Earth’s surface You Landscape Motion: When an object changes position over time when compared with a reference point

Dancing on the Ceiling Fred Astaire’s Dance

Speed Depends on Distance and Time Speed: The rate an object moves How long it takes an object to move over time Average Speed= total distance/ total time SI unit for speed= meters per second (m/s) Activity: Math Break pg 5

Velocity: Direction Matters Velocity: The speed of an object in a specific direction Planes velocity = 600 km/h south Activity: Self Check pg 6 Change in velocity= change in speed or direction Combining Velocities Combine two velocities in same direction= add together Combine two velocities in opposite directions= subtract smaller velocity from larger velocity

Section Review Pg 7

Acceleration Acceleration= The rate at which velocity changes Activity: Predictions: Calculating acceleration= Final velocity – Starting Velocity Time it takes to change velocity Meters per second per second = m/s/s = m/s 2 Activity: Math Break Acceleration= When velocity increases Deceleration= When velocity decreases Activity: List four examples

Acceleration Continued Circular motion: Continuous Acceleration Centripetal Acceleration= Change direction in a circle, changes velocity Figure 5 Graphing Acceleration: Acceleration= positive because velocity increases as time passes (Graph goes up) Deceleration= Graph goes down

Section Review Pg 10 Answers on pg 10 in book

What is Force? Chapter 1 Section 2

Forces Act on Objects Forces= A push or pull on an object Size and direction Newton= How force is measured SI unit Activity: Examples

Forces in Combination Net Fore= The combination of forces on an object May the Force Be With You Forces in the same direction= Added Together Forces in the opposite direction= Subtracted from one another Subtract the smaller force from the larger Figure 8: Pg 13 Self Check:

Unbalanced and Balanced Forces Unbalanced Forces= The object moves (Change in motion) Net force NOT EQUAL to 0 N Ex. Soccer Ball Balanced Force= the object doesn’t move Net force EQUAL to 0 N Ex. Bird’s nest in a tree Ex. Hat resting on your head

Friction: A Force That Opposes Motion Chapter 1, Section 3

The Source of Friction Friction: A force that opposes motion between two surfaces that are touching. Friction depends on two things: 1. Roughness of surfaces- The rougher the surface, the more friction Ex. Skating on ice vs. grass 2. Amount of force- the greater the force the more friction Ex. Massive object vs. Non massive object Activity: Pg 15: Connect to life…

Types of Friction Definition Two facts 3 examples

Types of Friction Sliding Friction- The friction of sliding an object across another object. Ex. Sliding a dresser on the floor or sledding down a hill Rolling Friction- The friction between wheels and the surface they are rolling on Ex. Pushing a grocery cart or roller skating Fluid Friction- The friction opposes the motion of objects traveling through a fluid (fluid may be gas or liquid) Ex. Swimming through water or a plane flying in the air Static Friction- Friction that keeps an object stationary Ex. Pushing on a wall

Discussion! Ways to reduce friction? Ways to increase friction? Activity: pg 20 apply

Friction Can Be Harmful or Helpful Harmful friction Holes in socks or knees of jeans Wind & water cause erosion Helpful friction Friction between pencil & paper Without friction, you would just slip & fall when you tried to walk

Friction Reduction Ways to reduce friction Lubricants- Substances applied to surfaces to reduce the friction between them Switching from sliding friction to rolling friction by the use of ball bearings Make surfaces that rub together smoother 25

Gravity: A Force of Attraction Chapter 1, Section 4 Gravity

All Matter Is Affected by Gravity Gravity = The force between two objects due to their masses All objects experience an attraction toward all other objects Earth’s gravitational force is large= pulls everything toward center of earth Ex. Chair stays in place Ex. Dropped objects fall to earth and not toward you

The Law of Universal Gravitation Sir Isaac Newton Law= All object attract each other and the force depends on the objects mass and distance Gravitational force increases when mass increases Ex. Cat is easier to pick up than elephant Gravitational force decreases when distance increases Ex. Planets Activity: Pg 24 Activity

Weight Is a Measure of Gravitational Force Weight= A measure of the gravitational force exerted on an object Mass= Amount of matter in an object (value does not change) Gravity is a force and is measured in Newton's 100 g is about 1 N