distance/displacement what’s the difference?
DESCRIPTION
Distance/Displacement What’s the difference?. Distance - how far in actual travel. Scalar – it has magnitude - ex: 300 meters around the track. Just like a car’s odometer, it keeps track of how far the car has traveled. Distance/Displacement What’s the difference?. - PowerPoint PPT PresentationTRANSCRIPT
Distance/DisplacementDistance/DisplacementWhat’s the difference?What’s the difference?
Distance - how far in actual travel. Scalar – it has magnitude - ex: 300 meters around the track.
Just like a car’s odometer, it keeps track of how far the car has traveled
Distance/DisplacementDistance/DisplacementWhat’s the difference?What’s the difference?
Displacement – distance between two points. Vector quantity– it has magnitude and direction. 20 miles Northeast
If a car goes 300 meters around the track and winds up where it started, the displacement is 0…..there is no distance between the beginning and ending point..
• Each car travels a distance of 2.5 meters from start to finish
• From start to finish, the car has a displacement of 0 meters
Start/Finish Line
DISTANCE vs. DISTANCE vs. DISPLACEMENTDISPLACEMENT
http://physics.info/displacement/desk-animated.html
Distance is total amount traveled (scalar quantity) while displacement is the description of the direct path between points using direction (vector quantity)
Let’s PracticeLet’s Practice Josselyn rides her bike to the nearest Verizon
store to get her new phone. The store is 2 km to the north. She then rides 1 km to the south to show her new phone off to Karla.
What distance did she travel? What is her displacement?
Let’s PracticeLet’s Practice James has a hot date with Chanice and picks
her up in his car. He takes her dancing at the club which is 15km away. After dancing, they drive back past her house and grab some food at the IHOP, 5 km to the west of her house.
What distance did they travel? What is their displacement?
LetLet
MOTION, SPEED & VELOCITYMOTION, SPEED & VELOCITY
Are these people moving? Are these people moving?
MotionMotion
A change in position relative to A change in position relative to a frame of referencea frame of reference
Frame of ReferenceFrame of Reference
Your perspective Your perspective or viewpoint to or viewpoint to determine if an determine if an object is movingobject is moving
How can you tell something How can you tell something is in motion?is in motion?
It changes position relative to a It changes position relative to a fixed pointfixed point
SPEEDSPEED
Fastest man in the world….who is this?Fastest man in the world….who is this? Usain “Lightening” BoltUsain “Lightening” Bolt
Constant SpeedConstant Speed
Changing equal amounts of Changing equal amounts of distance in equal units of timedistance in equal units of time
Speed = distance/timeSpeed = distance/time
What does Constant Speed What does Constant Speed look like?look like?
Motion Map: If I was eating ice cream and it Motion Map: If I was eating ice cream and it was dripping on the ground every second….was dripping on the ground every second….
VelocityVelocity
Speed plus a directionSpeed plus a direction
Example: 30 km/hr Example: 30 km/hr northnorth
Constant Velocity Lab
Groups of no more than 4 people. Everyone has a job. Write it on your sheet.
I should be able to come by and see who should be doing what. Timer Car start Car catcher Marker
Lab Report:Lab Report: Title: Constant Velocity LabTitle: Constant Velocity Lab Names of group membersNames of group members Purpose: Purpose: To describe constant motionTo describe constant motion Materials: Materials: Methods (Methods (in full sentencesin full sentences)) Data (Data (in tablein table – time & distance) – time & distance) Analysis (graph your Analysis (graph your averageaverage distance, distance, do do
a line of best fita line of best fit. Compare two points along . Compare two points along the line to get the car’s velocity)the line to get the car’s velocity)
Data Table
Time (s) Distance (cm) Trial 1
Distance (cm) Trial 2
Distance (cm) Trial 3
Average Distance (cm)
0 0 0 0 (0+0+0)/3 = 0
1
2
3
4
5
6…
Ave
rag
eD
ista
nce
(cm
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Time (seconds)