Speed

What is motion?

Motion: When an object changes position

Choral Read (Do not write!) Everyday, most of us use some form of transportation to get somewhere. Whether that form is a car, bus, a bicycle, or our own two feet, understanding the concept of speed is important in today's world of schedules and time crunches. It is the concept that helps us figure out how long it will take us to go from one place to another. The race track is a place where speed is especially important. During a race, the cars in the track cover the distance in as little time as possible, so they can win the race.

Speed: The amount of TIME it takes an object to move a given distance

Different Kinds of Speed: Instantaneous Speed: Rate of motion at a given moment – Ex. What a speedometer is measuring Constant Speed: Speed that does not vary. – Ex. Cruise Control holding your speed when driving on a straight, flat road Average Speed: Total distance divided by total time traveled. – Ex. If it takes you 3 hours (including bathroom and food breaks) to drive 175 mi. to San Diego, your average speed for the trip is 58 mph. Even if your instantaneous speed was 65+ mph the whole time you were on the interstate!

Speed formulas: Speed = d/t Speed = average speed d = distance t = time Sample Problem: 1. A runner travels 10 m in 5 seconds. What is her average speed? 2. A car travels 300 kilometers in 6 hours. What is the average speed of the car?

3. What is the speed of a skater, who travels a distance of 210 m in a time of 10 s? 4. What is the speed of a airplane that flies 7,200 km in 9 hrs?

For time t = d / speed t = time d = distance s = average speed Sample problem: 1. Sound travels at a speed of 330 m per second. How long does it take for the sound of thunder to travel 1,485 m?

For Distance d = t x speed Sample Problem: 1. The speed of a cruise ship is 50 km/hr. How far will the ship travel in 14 hours?

Calculating Speed ex

Graphing Speed

Velocity Speed of an object in a certain direction Formula V- velocity - Distance Final - Distance initial - Time final - Time initial

Calculating Velocity Calculate the average velocity of a dancer who moves 5 m toward the left of the stage over the course of 15 s.

Graphing Velocity

Acceleration Rate at which velocity changes Formula A= (final v - initial v) T

Calculating acceleration Calculate the acceleration of a car whose speed changes from 6 m/s to 12 m/s over a period of 3 s.

Graphing Acceleration