Straight motion

Let’s look the picture

Let’s look the picture

Old position

Let’s look the picture

Old positionNew position

New position

A

B

Can you tell me about rockets A and rockets B!

Old position

Let’s look the picture

Old positionNew position

New position

A

BWe can say, rocket A moving and B No !

Moving object is identified by its change of position from a certain point of reference

A change of position or displacement of an object from a certain point of reference is called MOTIONMOTION

In the lesson you are abble to :

1. Making a graph of displacement vs time

2. Finding the equation of speed

3. Identifying the application of constant straight motion in daily life

Science key word

1. Speed2. Velocity3. Acceleration4. Point of referent5. Motion6. Average speed7. Straight motion8. distance

Laju kecepatan Percepatan Titik acuan Gerak Laju rata-rata Gerak lurus perpindahan

Introduce

MotionMotion is a change of position or displacement of an object within a certain time interval

Various form of motion

Straight motionCircular motionParabolic motion

Point of referent is location which is considered fixed (at rest) and used to compare the initial and final position.

To understand how fast the object moves we have to know time needed to travel the distance of displacement.

Velocity Grahp

d (m)d2

d1

0 t1 t2 t (s)

distance (m) time (s)

d1 t1

d2 t2

Velocity Grahp

d (m)d2

d1

0 t1 t2 t (s)

Constt

d

t

d

2

2

1

1

This Constanta is Called

Velocity

VelocityVelocity is the change of position within a time interval

If distance (d), time interval (t) and velocity (v), we can write formula of velocity

t

dv

Velocity

t

dv

v

dt

The relationship among d, t, and v

tvd .v

dt

Velocity

d

The unit of velocity can be determine by unit of distance

divide by unit of timeIf unit of distance in SI is

meter, time interval is second, and velocity is meter per

second (m/s). In our daily life we usually use

km/h

Velocity

Velocity have two components :

1.Magnitude (absolute value) 2.Direction (arah)

Speed just have magnitude

VelocityBase on component that

contents of quantities, quantities can be derived in

two kind :1.Vector 2.Scalar

Velocity

For example1.If some one walking 5

km/hour toward east :a. his speed is 5 km/hourb. his velocity is 5 km/hour to east.

VelocityCalculating the velocityPada kenyataannya setiap object yang

bergerak kecepatannya selalu berubah (baik arah maupun nilainya)

Tidak mudah untuk memberikan contoh object yang bergerak dengan kecepatan tetap.

Untuk menjelaskannya digunakan konsep average speed (kecepatan rata-rata)

VelocityCalculating the velocityAverage speed is the total

traveled distance divided by the time needed to travel that distance.

t

dv

v = average speedd = total distancet = time total

Motion ber-sifat relatif Benda dikakatan bergerak atau

tidak tergantung dari titik acuan (point of reference) yang digunakan

For example Seseorang yang ber ada dipinggir

jalan akan melihat orang-orang yang berada di dalam mobil bergerak, tetapi antara penumpang dan sopir tidak bergerak.

Straight Motion

Straight motion is motion that have

Identify pleace!

Identify pleace!