Static body. The object does not change its position as time passes .

Dynamic body :The object changes its position as time passes.

Types of motion

Translational motionPeriodic motion

The motion of body from point to another.

(in straight line – in curved line)

It repeat its position in space at equal interval time.

Scalar and Vector

Scalar QuantityVector Quantity

The quantity which has magnitude only such as

(Time – volume – mass – distance -

speed)

Has direction and magnitude such as

(Velocity – displacement -

acceleration )

Check your understandingCategorize each quantityCategorize each quantityas being either a vector or a scalar.

QuantityCategory

5 m ) Scalar – Vector )

30 m/sec, East ) Scalar – Vector )

5 m ., North ) Scalar – Vector )

20 degrees Celsius ) Scalar – Vector )

256 bytes ) Scalar – Vector )

4000 Calories ) Scalar – Vector )

Check your understanding

QuantityCategory

5 m ) ScalarScalar – Vector )

30 m/sec, East ) Scalar – VectorVector )

5 m ., North ) Scalar – VectorVector )

20 degrees Celsius ) ScalarScalar – Vector )

256 bytes ) ScalarScalar – Vector )

4000 Calories ) ScalarScalar – Vector )

Distance (d) and displacement (X)

DistanceDisplacement

The actual path the body moved in it.- The distance traveled in a certain

direction.- Or It is the change in the position

Scalar Vector

Distance is 5 meters.Displacement is 5 meters. rightward

Distance (d) and displacement (X)

when the car travels from (A) to (B) to (C) and then to (D).the distance "the path"=10+3+2 = 15Km.

The displacement between (A) initial point to (D) end point is 9Km

Mansora

MetMazah

Dekerness

A

D

DemohC

B

10Km

3Km

2Km

9Km

Ex: A car travels from the A to B,C, and D in the direction shown .. Find the distance and displacement in each of the following.1-When the car travels from A to B2- When the car travels from A to C3- When the car travels from A to D4-When the car travels from A to B ,C,D then to A

30Km

50Km

50Km50Km

A B

CD

Ex: A car travels from the A to B,C, and D in the direction shown .. Find the distance and displacement in each of the following.1-When the car travels from A to B2- When the car travels from A to B to C3- When the car travels from A to B to C to D4-When the car travels from A to B ,C,D then to A

30Km

50Km

50Km50Km

A B

CD

Answer:

From A to Bfrom A to B to Cfrom A to B to C to DFrom A to B to C to D

to A

Distance (km)3070120170

Displacement (km)3050500

Use the diagram to determine the resulting displacement and the distance traveled by the skier during these three minutes

Worksheet 1

Speed and Velocity

SpeedVelocity

The change of distance per unit time.How fast an object is moving.50 m/s is a speed.

The change of displacement per unit of time.How fast in which direction.50 m/s north is a velocity.

)/( smt

dspeed

)/( smt

XVelocity

Types of velocity The uniform (constant) velocityThe non-uniform velocity

Displacement changed by equal amounts at equal intervals of time.

Displacement changed by different amount at equal interval of time.

t

xV

Slope

Instance velocity: It is the velocity of moving body at certain instance .The average velocity: Is the total displacement traveled per the total time

)/( smt

XV

Ex: A car moves at constant speed of 20m/s how far is the car after an hour?

)/( smt

XV

GivenFindRemarks

v=20m/st=1h×60m×60s = 3600s

X distance

Distance X = v × t = 20 × 3600 = 72000 m

The physics teacher walks 4 meters East, 2 meters South, 4 meters West, and finally 2 meters North. The entire motion lasted for 24 seconds. Determine the average speed and the average velocity.

ProblemProblem

ProblemProblemThe physics teacher walks 4 meters East, 2 meters South, 4 meters West, and finally 2 meters North. The entire motion lasted for 24 seconds. Determine the average speed and the average velocity.

The physics teacher walked a distance of 12 meters in 24 seconds; thus, her average speed was 0.5 m/s.

displacement is 0 meters, her average velocity is 0 m/s

is the change of velocity in one second

)/( 2smt

Va

An object is accelerating if it is changing its velocity .

ProblemProblem

A car moves from rest with uniform acceleration 2 m/s2 . During 4 seconds .Calculate the final speed.

A car moves from rest with uniform acceleration 2 m/s2 . During 4 seconds .Calculate the final speed.

ProblemProblem

)/( 2smt

Va

Vi = 0 m/s VfAcceleration = 2 m/s2

)/(sec4

2smVV

a if

Then Vf = 2 × 4 = 8 m/s2

Use the equation for acceleration to determine the acceleration for the following two motions

Use the equation for acceleration to determine the acceleration for the following two motions

Use a = )vf - vi) / t and pick any two points.

a = )8 m/s - 0 m/s) / )4 s) a = )8 m/s) / )4 s)

a = 2 m/s/s

a = )0 m/s - 8 m/s) / )4 s) a = )-8 m/s) / )4 s)

a = -2 m/s/s

Observe the animation of the three cars below

1. Which car or cars (red, green, and/or blue) are undergoing an acceleration? Study each car individually in order to determine the answer.

The green and blue cars are speeding up , thus covering an increasing distance in each second.

Red car has constant speed.

Observe the animation of the three cars below

2-Which car (red, green, or blue) experiences the greatest acceleration?

The blue car has a greater acceleration . It is changing it velocity at more rate.

Observe the animation of the three cars below

3-Consider the position-time graph at the right. Each one of the three lines on the position-time graph corresponds to the motion of one of the three cars. Match the appropriate line to the particular color of ca

Red car = B constant slop

Green = C more gradually

Blue car = A

Describe the motion depicted by the following velocity-time graphs. In your descriptions, make reference to the direction of motion (+ or - direction), the velocity and acceleration and any changes in speed (speeding up or slowing down) during the various time intervals (e.g., intervals A, B, and C)

he object moves in the + direction at a constant speed - zero acceleration (interval A). The object then continues in the + direction while slowing down with a negative acceleration (interval B). Finally, the object moves at a constant speed in the + direction, slower than before (interval C).

Ex: draw the graph relating d and t , then answer .the object moves with 1-an increasing velocity2-a decreasing velocity3-a uniform velocity

the object moves with1-an increasing acceleration 2-a decreasing acceleration3- zero acceleration

d(m)102030

t(s)123

Worksheet 2

Relative Speed) : تعالى بال قوله ال�ج ى تر و

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عل�ون تف� ا ب م ب ير1 خ ن�ه� إ ء6 ي� ) ش : [.88النمل]

Jack

Jill

Speed is not absolute, it is dependant on the observer.  That is why we say it is "relative" to the observer

Observer

Jill sees Jack at rest and Jack sees Jill the same way

Jack

JillObserver

Mother is the observer

the Speed of A relative to B ,     

the Speed of B relative to A is                   .

The expression "the speed of A relative to B" is "the speed of A in the coordinate system where B is always at rest".

Relative SpeedAll motion is relative to the observer or to some fixed object.

Relative SpeedAll motion is relative to the observer or to some fixed object.

Two cars moving along the same straight road , The speeds are relative to the ground.Measurements of position and speed are made from some point on the ground, point O.Speed of car A relative to point O = vA(O) = 40ms-1Speed of car B relative to point O = vB(O) = 30ms-1

What is the speed of car A relative to car B?A moves 10m away from B in the positive sense and B moves 10m away from A in the negative sense.

Therefore, vA(B) =+10ms-1 and vB(A) = -10ms-1vB(A) = vB(O) - vA(O) = 30 – 40 = -10ms-1

Suppose that we want to know the speed of car A relative to car B Worksheet 3

Referenceshttp://www.physicsclassroom.com/Class/1DKin/U1L1b.cfmhttp://en.wikiversity.org/wiki/Motion_in_one_dimension

http://www.gwc.maricopa.edu/class/phy101/Flash/displacement%20and%20distance%20traveled.htm

http://video.google.com/videoplay?docid=-7218860555420700863 #

http://faraday.physics.utoronto.ca/PVB/Harrison/Flash/ClassMechanics/ConstantAccel/ConstantAccel.html

http://www.upscale.utoronto.ca/PVB/Harrison/Flash/http://www.regentsprep.org/regents/physics/phys01/velocity/relative.htm

How to solve physics problem (Rebort Oman - Danial Oman )Fundamentals of Physics Extended, 8th Edition [Jearl Walker] , Cleveland State University , John Wi ley & Sohs, lnc. 2007 , downloaded from ( http://www.quickbook.0fees.net )Student book (science for prep3 – term1 – 2010-2011)

Mr. Hmady Eid (website)

http://hebaky-physics.wikispaces.com/