Drs DIDIK PRADIGDOSMA NEGERI 3 SEMARANG

BY :

1. DISTANTDistant is length of the line to be reach.

2. DISPLACEMENTDisplacement is change of position thing in certain line.

The formula of displacement :

ΔX = Xf –Xi

ΔX = Displacement Xf = Final Position Xi = Initial Position

According to the definition of motion, where the animals are moving and which are not moving. Explain why.

8

6Distance =

Displacement =

scalars

vectors

How Distance and displacement

distance

displacement

A -5 -4 - 3 - 2 - 1 O 1 2 3 4 5 B

A -5 -4 - 3 - 2 - 1 O 1 2 3 4 5 B

HOW MUCH distance traveled (A-B-O)? displacement OF HER HOW MUCH?

HOW MUCH distance traveled (A-B-O)? Displacement of her how much ?

A -5 -4 - 3 - 2 - 1 O 1 2 3 4 5 B Hom much distance traveled ( A-B-O ) ?Displacement of her how much ?

28

v v

x = s

v v

x1 ; t1

x = v x t

v =

t =

stsv

x2 ; t2

v

x2 - x1v =

v =

t2 - t1

xt

t

v

t

Area = distance (s)

s

t

kece

pata

n

instantaneous velocity

Distance Graph (s) - time (t) Graph of velocity (v) - time (t) Graphics acceleration (a) - time (t)

Jarak (s) kecepatan (v) Percepatan (a)

GRAPHS IN STRAIGHT MOTION irregular (GLB)

Seseorang mengendarai sepeda

motor, mula-mula kecepatannya 18

km/jam, setelah 10 sekon kemudian

kecepatannya menjadi 54 km/jam. Berapa percepatan sepeda

moto tersebut

Diketahui :v1= 18 km/jam = 5 m/sv2= 54 km/jam = 15 m/st = 10 sDitanyakan : a = ?

Someone driving a car withfixed speed 15 m / s. Specify:a. Distance beaten after 4 s, 5 s.b. The time it takes for me    traveling distance of 3 km

Diketahui :v= 15 m/s

Ditanyakan :a. s =…. ? (t = 4 s) s =…. ? (t = 5 s) b. t = …. ? ( s = 3 km = 3000

m )

Sebuah benda bergerak ditunjukkan

seperti grafik diatas. Hitunglah jarak

yang ditempuh benda setelah berge-

rak selama a. 4 s b. 10 s c. 1 menit

4 10

5

t(s)

v (m/s)

0

Diketahui :v= 5 m/s (kecepatan tetap)Ditanyakan :a. s =…. ? (t = 4 s)b. s =…. ? (t = 10 s) c. s = …. ? (t = 1 mnt=60 s )

THINGS MOVING WITH NO FIXED SPEED

ACCELERATION ( a + ) DICELERATION ( a - )

Jarak (s) kecepatan (v) Percepatan (a)

Distance (s) - time (t) velocity (v) - time (t) acceleration (a) - time (t)

CHANGES IN STRAIGHT MOTION GRAPHS irregular (GLBB)on Accelerate (a +)

s = Vo.t + ½ a.t2 V = Vo + a.t

V2 = Vo2+ 2a.s

Jarak (s) kecepatan (v) Percepatan (a)

Distance (s) - time (t) velocity (v) - time (t) acceleration (a) - time (t)

CHANGES IN STRAIGHT MOTION GRAPHS irregular (GLBB)on Deceleration (a -)

s = Vo.t - ½ a.t2 V = Vo - a.t

V2 = Vo2- 2a.s

BLBB flas.swf

1. A motorist drives north for 30 minutes at 72 km/h and then stops for 30 minutes. He then continues north, traveling 130 km in 2 hours and then he turn to south travelling 50 km in 1 houra. What is his total displacement?b. What is his average velocity?

c. What is his average speed?

SAMPLE PROBLEMS

A B

C

6 km

8 km

Find:a. Average speed of carb. Average velocity of car

2. A car moved from A to B in 10 minutes, and continues to c in 5 minutes.Look at the picture!

3. A toy car moves from A to D through B and C in 10 s .Find : a. The average speedb. The average velocity

A B

C D

12 m

9 m

6 m

Created by Rozie 14

3. Vertical Motion

a. Upward Vertical Motion

tvv

s

gttvs

gsvv

gtvv

t

t

t

2

2

0

22

10

20

2

0

g = gravitational acceleration (m/s2)vH = velocity at point H (m/s)sH = the highest point reached (m)tH = time to reach highest point (s)

H

the highest point reached (H)

V0

g

vs

g

vt

v

H

H

H

2

0

20

0

ground

vt

Created by Rozie 15

b. Downward Vertical Motion

tvv

s

gttvs

gsvv

gtvv

t

t

t

2

2

0

22

10

20

2

0

g = gravitational acceleration (m/s2)vt = final velocity/velocity at certain t time (m/s)v0 = initial velocity (m/s)s = displacement/distance(m)t = time interval(s)

ground

vt

v0

c. Free Fall Motion (v0 = 0)

tv

s

g

stgts

gsvgsv

gtv

t

tt

t

2

2

22

22

1

2

Created by Rozie 16

GRK-JATUHBEBAS-GRAFIK.swf

1. A Car move (mendekati) traffic light with initial velocity 50 m/s. At distant 125 m.The Traffic light shown the red lamp.Determine the decceleration of the car to stop at traffic light!

2. An apple fall from the tree with the time of 2 s.Find : a. The velocity to hit the ground

b. The high of apple with the ground before fall

3. A boy thrown a ball vertically upward with initial velocity of 40 m/s.Find : a. The maximum high

b. Time to reach high of 60 m

4. A cat run 110 m to the east latter 25 m to the north before finally latter to west distant 50 m. Find the distant and displacement cat to pay from arigin point!

1. A car moves on a linear path with constant speed 72 km/hour. Determine:a. The distance travelled by the car in 5 minutesb. time to travel distance 360 km2. How the velocity of the object in 15 minutes traveling the distance of 20

km?3. An object moves and expressed by the following position-time graph

14

4 6t (s)

x (m)

6

Determine:a.Velocity at time t = 5 sb.Average velocity in time interval t= 0 s until t= 6 s

SAMPLE PROBLEMS

Created by Rozie 19

a. Describing motion of the object!b. Find the velocity of the object at time t= 3 s, t= 11

s, and t= 15 sc. Find the average velocity at time interval t= 9 s

until t= 14 s

14

1

-6

4

4 9 11 20 t (s)

S (m)

3. An object moves and expressed by the following displacement-time graph

4. A car moves from rest and accelerated to a speed of 30 m/s in 6 seconds. How the distance travelled by the car?

5. How long does it take for a car to change its velocity from 10 m/s to 25 m/s if the acceleration is 5 m/s2? Created by Rozie 20

7. A body moves as described by the following v-t graph a. Describe the motion.b. What is the distance travelled during the motion?c. What is instantaneous speed at time t= 2 s?d. What is the average speed for the motion?.e. What is the average acceleration for the motion?.f.What is the average acceleration for time interval t= 2 s until t= 8sg. Instantaneous acceleration at time t= 6 s

6. The speed versus time graph below represents the motion of a car. Approximately how far did

the car travel during the first 5 seconds?

Created by Rozie 21

8. A car moves in 36 km/h and braked with constant acceleration and stopped after 5 m. How long does it take to stop?

9. A car moves with speed of 25 m/s then braked and required distance of 40 m change its speed becomes 15 m/s . Find total distance travelled until the car was stopped.

10. A car is moving with the speed of 72 km/h. Because at its front as far as 200 m a cat is crossing the road, then driver brakes the car with deceleration 5 m/s2. Whether the cat was hit by a car?11. Two cars, R and B are separated each other at a distance 600 m travelling in the opposite direction. Car R and B move with constant velocity of 20 m/s and 10 m/s respectively. When and where do car A and B meet if:

a. both of them departs at the same time. b. Car B departs 5 s earlier

600m

12. Two cars, A and B are separated each other at a distance 600 m travelling in the opposite direction. Car A with constant velocity of 10 m/s and B depart from rest with acceleration 2 m/s2. When and where do car A and B meet if both of them departs at the same time.

13. When and where do car B overtakes car R?

t= 0 s, v = 20 m/s (constant)

t= 0 s, v = 0 m/s, a = 2 m/s2

Created by Rozie 22

15. An object fall freely from the rooftop of a building, and then hit the ground in time interval of 2 seconds. Calculate:

a. The velocity to hit the groundb. The high of building16. A boy shoot a projectile vertically upward with initial velocity of 200 m/s. Find:a. The maximum highb. Time to reach high of 500 mc. Time to reach the highest pointd. Velocity of projectile has moved at 10th seconds e. Velocity of projectile in high of 2 km17. Someone falls a stone with initial velocity of 20 m/s from peak of tower which has

height 225 m above the earth. Determine:a. Time required by the stone to reach the earthb. Velocity of the stone when reaching the earthc. Height of stone from earth when the velocity is 30 m/s

100 m

14. When and where do car R overtakes car B if:a. Car R and B move with constant velocity of 10 m/s and 5 m/s respectively and

both of them departs at the same time b. Car R and B move with constant velocity of 10 m/s and 5 m/s respectively and car

B departs 5 s earlierc. Car R move with acceleration 2 m/s2 from rest and B move with constant velocity

of 10 m/s

Created by Rozie 23

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12

10

8

6

4

2

●

●

5 10 15

●

A

B C

y (m)

t (s)

18. The diagram below shows a position-time graph of an object which travelling vertically

Calculate:a.Average velocity at time interval 0.5 s – 7.5 sb.Average velocity at time interval 0 s – 14 sc.Instantaneous velocity at t= 1.5 sd.Instantaneous velocity at t= 7.5 se.Instantaneous velocity at t= 10 s

Created by Rozie 24