Chapter 11Chapter 11

MotionMotion

Sec. 11.1 Frame of reference

A system of objects that are not moving with respect to one another

Used in order to see motion

Describes motion accurately

Relative MotionRelative MotionMovement in relation to a frame of Movement in relation to a frame of referencereference

Ex. People in a car appear to be moving Ex. People in a car appear to be moving to the people on the side of the roadto the people on the side of the roadBut when people in the car look at one But when people in the car look at one another they do not seem to be moving another they do not seem to be moving at all.at all.

Video on frame of referenceVideo on frame of referenceOLD SCHOOLOLD SCHOOL

http://archive.org/details/frames_of_reference

http://www.amnh.org/learn/pd/physical_science/week2/frame_reference.html

Interactive practice with frame of reference

http://www.physics-chemistry-interactive-flash-animation.com/mechanics_forces_gravitation_energy_interactive/frame_of_reference_motion_child_ball_train.htm

DistanceLength of a path between 2 pointsLength of a path between 2 points

The SI unit for distance is the The SI unit for distance is the metermeterVs.Vs.

DisplacementDisplacementLength of straight line from start to Length of straight line from start to endend

VectorVectorQuantity that has magnitude (size, Quantity that has magnitude (size, length or amount) and directionlength or amount) and direction

Arrows represent vectors (they show Arrows represent vectors (they show a numerical value and a direction)a numerical value and a direction)

Resultant VectorResultant VectorVector sum of 2 or more Vector sum of 2 or more vectorsvectors

Points directly from the Points directly from the starting point to the starting point to the ending pointending point

Distance vs displacementDistance vs displacement

http://physics.info/displacement/

Go over this with the class before the activity

Quick LabQuick Lab

Turn to page 330Turn to page 330

Obtain a sheet of graph paper and a Obtain a sheet of graph paper and a rulerruler

Follow the direction for the quick labFollow the direction for the quick lab

Turn your lab in 1paper with two Turn your lab in 1paper with two names on it.names on it.

Sec 11.2 Sec 11.2 speedspeedRatio of the distance an object Ratio of the distance an object moves to the amount of time the moves to the amount of time the object movesobject moves

Write formula page 333Write formula page 333

Average Average speedspeed-- entire trip entire trip

Instantaneous Instantaneous speedspeed-- measured at a measured at a particular instant (Ex. Speedometer)particular instant (Ex. Speedometer)

Average Average SpeedSpeed

Average Average SpeedSpeed = = Total DistanceTotal Distance

Total TimeTotal Time

V`= V`= dd

tt

http://www.nbclearn.com/nfl/cuecard/50770

Average Average SpeedSpeedTotal distance/total time

Ex. Drove 50 m in 28 sec, drove 200 m in 180 sec, stopped for 50 sec, drove 100 m in 100 sec. What is average speed?

50 m +200m +0 m + 100 m=350m28 s + 180 s + 50 s + 100 s=358s= 350 m /358 s = _0.98__ m/s

More practiceMore practice

LetLet’’s work through math s work through math skills/practice page 333 togetherskills/practice page 333 together

Copy steps into your notes from page Copy steps into your notes from page 333333

Practice #1 Answer 0.1 km/minPractice #1 Answer 0.1 km/min

Practice #2 Answer 62 km/hrPractice #2 Answer 62 km/hr

More v=d/tMore v=d/t

Icurio activityIcurio activity

http://www.icurio.com/goExternal?np=/templates/sections/external/external.ftl&pp=/templates/sections/framework/error.ftl&evlCode=272477&productName=icurio&al=High

Graphing MotionGraphing Motion

You tube Moving manYou tube Moving manhttp://www.youtube.com/watch?v=x2ve5yucNPQ

http://zonalandeducation.com/mstm/physics/mechanics/kinematics/xvaVsTime/xVsTime.html

Click the link below to do the interactive

Click this link next and do this interactive second

http://www.mangahigh.com/en/maths_games/shape/speed_distance_time/distancetime_graphs

Practice with graphsPractice with graphs

http://www.thatquiz.org/tq/http://www.thatquiz.org/tq/previewtest?C/F/D/L/previewtest?C/F/D/L/3492129252911634921292529116

How does a speedometer work?How does a speedometer work?

It measures distance (the number of It measures distance (the number of times the tires turn) and times the tires turn) and speedspeed

( their rate of turning)( their rate of turning)

VelocityVelocityDescription of both Description of both speedspeed and and directiondirection of motion of motion

Velocity is a Velocity is a vectorvector

A change in A change in speedspeed, , directiondirection, or , or both will result in a change of both will result in a change of velocityvelocity

Discovery ed interactiveDiscovery ed interactive

http://app.discoveryeducation.com/

http://www.physicsclassroom.com/http://www.physicsclassroom.com/class/vectors/u3l1b.cfmclass/vectors/u3l1b.cfm

Sec.11.3 Sec.11.3 AccelerationAcceleration

The rate at which velocity changesThe rate at which velocity changes

Changes Changes speedspeed, , directiondirection, or both, or both

Acceleration=Acceleration=change in velocitychange in velocity total timetotal time

a= a= (v(vff-v-vii)) tt

Extra HelpExtra Help

To rearrange the equation to solve To rearrange the equation to solve for other variables, especially vfor other variables, especially v i i or vor vff

1.multiply both side of the equation 1.multiply both side of the equation by tby t

2.cancel the t/t on the right side of 2.cancel the t/t on the right side of the equationthe equation

3.add v3.add vii to both sides of the equation to both sides of the equation

Practice thisPractice this1. a sprinter accelerates from the starting 1. a sprinter accelerates from the starting block to a speed of 8.0 m/s in 4.0 s. What block to a speed of 8.0 m/s in 4.0 s. What is the magnitude of the sprinters is the magnitude of the sprinters acceleration?acceleration? (2.0 m/s(2.0 m/s22))2. a car is traveling at 14 m/s. Stepping 2. a car is traveling at 14 m/s. Stepping on the gas pedal causes the car to on the gas pedal causes the car to accelerate at 2.0 m/saccelerate at 2.0 m/s22. How long does the . How long does the driver have to step on the pedal to reach a driver have to step on the pedal to reach a speed of 18 m/s? speed of 18 m/s? (2.0 s) (2.0 s)

Free fallFree fallhttp://www.regentsprep.org/Regents/physics/phys01/accgravi/index.htm

Click and go through the link with the class.

ConstantConstant Acceleration Acceleration

A steady change in A steady change in velocityvelocity

Changes the same Changes the same amount each secondamount each second

InstantaneousInstantaneous Acceleration Acceleration

How fast a velocity How fast a velocity is changing at a is changing at a specific instantspecific instant

Graphs of Accelerated MotionGraphs of Accelerated Motion

SpeedSpeed-time graph-time graph

The slope of the line on the graph is the The slope of the line on the graph is the accelerationacceleration

Constant acceleration is demonstrated Constant acceleration is demonstrated with a straight line or with a straight line or linear graphlinear graph

Accelerated motion is demonstrated with Accelerated motion is demonstrated with a curved line or a curved line or nonlinear graphnonlinear graph

ex. A car at a stop light accelerates (when green) to 15m/s in 5 sec.

What was their acceleration?

Ex. A car traveling 30 m/s comes to a stop in 3 sec. What was their

acceleration?

LetLet’’s practices practice

Page 346Page 346

Math skills copy the exampleMath skills copy the example

Math PracticeMath Practice

#1 answer -0.5 m/s#1 answer -0.5 m/s22

#2 answer 36 m/s#2 answer 36 m/s

#3 answer 19.6m/s #3 answer 19.6m/s

#4 answer -25 m/s#4 answer -25 m/s

Compare speed and velocityCompare speed and velocity

http://www.youtube.com/watch?http://www.youtube.com/watch?v=DRb5PSxJerMv=DRb5PSxJerM

Wrap up and review of Speed, Wrap up and review of Speed, Velocity and AccelerationVelocity and Acceleration

SongSonghttp://www.youtube.com/watch?v=rZo8-ihCA9E