Chapter 1 Motion and Momentum SEC. 1 What is Motion?

The Students Will: Define Speed, velocity and displacement Graph Motion

Terms to Know Speed Average Speed Instantaneous Speed Velocity Distance Displacement

What is Motion? Movement--------- changes in position Requires a point of reference (starting point)

What is Distance? The length of the route one travels Ex. Distance from your house ------ school Expressed in Meters (m)/ Kilometers (km)

What is Displacement? Includes the distance between the starting and ending points, and the direction in which you travel. Ex. 40 m east

What is Speed? The distance traveled divided by the time taken to travel the distance is called speed. S= distance (meters) time (seconds)

A passenger train travels from Boston to New York a distance of 350 km in 4 hours. What is the train’s speed?

If the car travels 400 m in 20 seconds how fast is it going?

Bart ran 5000 meters from the cops and a speed of 6 meters/second before he got caught. How long did he run?

If it takes Ashley 3 seconds to run from the batters box to first base at a speed of 6.5 meters per second, what is the distance she covers in that time?

2 Kinds of Speed Average Speed - The total distance traveled divided by the total time taken. Instantaneous Speed -the speed of an object at one instant of time.

Distance Time Graph -Represents the motion of an object

What is Velocity? The speed of an object and the direction of its motion is called velocity.

Sec. 2 ACCELERATION -

What is Acceleration? The change in velocity divided by the time it takes for the change to happen. -happens when an object speeds up or slows down.

3 Ways to Accelerate: SPEEDING UP SLOWING DOWN CHANGING DIRECTION

Formula: Acceleration= final speed (m/s) – initial speed (m/s) time (s) a = sfi – si t

ACCELERATION NEGATIVE POSITIVE -OBJECT SLOWS DOWN -OBJECT SPEEDS UP ZERO -SPEED DOES NOT CHANGE

SPEED TIME GRAPH

Acceleration Problems 1. A roller coaster car rapidly picks up a speed as it rolls down a slope. As it starts down the slope, its speed is 4 m/s . But 3 seconds later, at the bottom of the slope, its speed is 22 m/s. What is its acceleration?

2. A cyclist accelerates from 0 m/s to 8 m/s in 3 seconds 2. A cyclist accelerates from 0 m/s to 8 m/s in 3 seconds. What is his acceleration? Is this acceleration higher than that of a car which accelerates from 0 to 30 m/s in 8 seconds?

SEC 3 MOMENTUM

The Students will: Explain the relationship between mass and inertia. Define Momentum Solve problems using the Momentum Formula

Terms to Know: Mass Inertia Momentum

What is Mass? The amount of matter in an object is called Mass. Units-kilograms (kg)/grams (g), pounds (lbs)

The tendency of an object to resist change (position, movement) is called inertia. --objects with mass – inertia

What is Momentum? The measure of how hard it is to stop the motion of an object is called Momentum Momentum (p) = mass (kg) x velocity (m/s) p = mv

Law of Conservation of Mass: The total momentum of the objects that collide is the same before and after the collision.