MOTION SPEED, VELOCITY, AND ACCELERATION

WHAT IS MOTION? How would you describe motion? Okay, now try it again… this time without using the word “Move” “Movement” or Motion”. Quick Write (2 min)

AIR TROLLEYS Air Trolley Construction Explore movement and think about ways to describe it. As a group decide on a way to measure the movement you observe and then record your measurement, including drawings. What are some important things to consider when measuring the movement?

Motion occurs when there is a change in position (location) of an object with respect to a starting reference point.

POSITION Position is the location of an object. The change in position is determined by the distance and direction of an object’s change in position from the starting point. Position is represented by the variable x. “x marks the spot!”

REFERENCE POINT The object or point from which movement is determined Movement is relative to an object that appears stationary Earth is the most common frame of reference/ reference point

QUESTIONS What is the frame of reference for the sunset? What is the most common frame of reference?

Day 2

GIVING DIRECTIONS We will blindfold one person. Now I will draw a simple picture for the rest of the class to see. A non-blindfolded person will give directions for the blindfolded person to recreate the original image on the board. You try it! Did you create a reference point? Why are good directions so important?

DIRECTION Direction is the line, or path along which something is moving, pointing or aiming. Direction is measured using a reference point with terms such as up, down, left, right, forward, backward, toward, away from, north, south, east or west.

GIVING DIRECTIONS SegmentDistance (m)Direction A7East B6North C2West DLess than a meterUp What was the total distance traveled? What was the displacement?

WHAT IS DISPLACEMENT? Displacement is the distance between the initial position (reference point) and the final position taking the SHORTEST route.

Distance: total ground covered, regardless of direction Displacement: overall change; final position – initial position; shortest route If you walk 5 blocks north and 3 blocks south, what total distance have you traveled? What is your displacement? What is the difference in Distance and Displacement?

1. What is the displacement of the cross- country team if they begin at the school, run 10 miles and finish back at the school? 2. What is the distance and the displacement of the race car drivers in the Indy 500?

YOU TRY IT A squirrel climbs 12 meters up a tree and then 7.5 meters back down the tree. What is the total distance that the squirrel traveled? What is the displacement of the squirrel?

1)During basketball practice Marcus runs the length of the basketball court 10 times. (the length of a basketball court is 94ft) What is Marcus’ total distance traveled? What is Marcus’ total displacement? 2) Liam leaves a history classroom and walks 10 meters north to a drinking fountain. Then he turns and walks 30 meters south to an art classroom. What is Liam's total displacement from the history classroom to the art classroom? What is Liam’s total distance traveled?

CHALLENGE QUESTION Seth walks 5 meters north, then 4 meters east, and finally 2 meters south. What total distance did he travel? What is Seth’s displacement?

Day 3

Find Mrs. Clark’s average speed walking across the classroom. THINK: What do you need?

SPEED! Motion can also be described by the relationship between distance an object travels and the period of time it travels. This measurement if motion is a rate. Speed is a measure of how fast something moves a particular distance (for example meters) over a given amount of time (for example, seconds).

Speed vs. Velocity

QUESTION When can you determine how fast you are going in a jet plane?

SPEED The units for speed: meters/second (m/sec) kilometers/hour (km/hr) Speed that does not change is constant speed.

AVERAGE SPEED Total distance divided by the total time Formula: total distance total time

TO FIND AVERAGE SPEED, FIND TOTAL DISTANCE AND DIVIDE BY TOTAL TIME, DON’T AVERAGE TWO SPEEDS! Harli jogs 400 meters in 120 seconds, then jogs 200 more meters in 40 seconds. What is Harli’s average speed?

PRACTICE 1) Brendon runs 25 meters in 4.3 seconds, then runs another 20 meters in 3.3 seconds, but gets tired and runs 15 more meters in 4.4 seconds. What is Brendon’s average speed? 2) I walk 20 blocks north, then 15 blocks east, then 20 blocks south, all in 1 hour total. What is my average speed?

YOU TRY IT! Kayla jogs 400 meters in 120 seconds, then jogs 200 more meters in 40 seconds. What is Kayla’s average speed?

QUESTIONS What is motion? What is speed? How is it calculated? What is average speed?

VELOCITY Speed in a given direction Velocities in the same direction combine by adding Velocities in different directions combine by subtracting

INTERESTING FACT Rockets are launched in the same direction of the earth’s rotation to get an extra boost of 1800 km/hr to its speed

DISCUSSION QUESTIONS See if you can come to a consensus on answers to these questions: 1.A yellow car is heading East at 100 km/h and a red car is going North at 100 km/h. Do they have the same speed? Do they have the same velocity? 2.A 16-lb bowling ball in a bowling alley in Del Mar heads due north at 10 m/s. At the same time, a purple 8-lb ball heads due north at 10 m/s in an alley in La Jolla. Do they have the same velocity?

WELCOME TO HIGH SCHOOL: SCALARS VS. VECTORS Scalars are quantities that are fully described by a magnitude (or numerical value) alone. Vectors are quantities that are fully described by both a magnitude and a direction.

Exit Slip: What is the main difference between speed and velocity?

Day 5

DO NOW QUESTIONS: How is velocity different from speed? Which two factors determine an object’s velocity?

ACCELERATION The change in velocity Acceleration is measured in m/sec/sec or m/sec 2 Formula is: (final velocity - original velocity)/time

DECELERATION VS. ACCELERATION A decrease in velocity is negative acceleration A distance-time graph for acceleration is always a curve

CENTRIPETAL ACCELERATION Acceleration directed toward the center of circular path

QUESTIONS What is acceleration? What is the shape of a distance-time graph for acceleration? What is centripetal acceleration?

MOMENTUM Momentum is equal to the mass of an object times its velocity momentum= mass x velocity

CONSERVING MOMENTUM The law of conservation of momentum states that the total momentum is NOT lost, only transferred

QUESTIONS What is momentum? What happens to momentum as the mass of a moving object increases? What is the formula for momentum? What is the law of conservation of momentum?