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In this chapter, students will learn about motion, speed, velocity, displacement, and momentum. They will define these terms, graph motion, and solve problems using the formulas for speed, acceleration, and momentum.
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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 thedistancebetween 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.
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 -OBJECT SLOWS DOWN POSITIVE -OBJECT SPEEDS UP ZERO -SPEED DOES NOT CHANGE
Acceleration Problems 1. A roller coaster car rapidly picks up a speed as it rollsdown 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. What is his acceleration? Is this acceleration higher than that of a car which accelerates from 0 to 30 m/s in 8 seconds?
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.