Motion Diagrams. Sometimes we want to look at an object at one point in time – that means its position (x).

Motion Diagrams

Sometimes we want to look at an object at one point in time – that means its position (x).

Example 1:

A stationary pool ball on a surface.

• Any object that is at rest for an instant, occupies only a single position and is indicated with a single dot:

• If the object stands still for several beats or seconds, indicate it with several dots one above another:

This object is not moving for3 beats of the Metronome or 2 time intervals.

• If the object stands still for a long time place a circle around one dot:

Motion Diagrams of Moving Objects

Sometimes we want to observe the movement of objects. We call this change in position x.

x = Xf - Xi

Example 2: How does a motion diagram show a skateboarder moving down a sidewalk at a constant speed?

1st There is equal distance between each point.

2nd This makes each arrow the same length.

3rd The arrows point in the direction that the skater is moving.

What will the motion diagram look like for this

X vs t graph?

Draw it above the line provided!

Example 3: The Tortoise and the

Jack-a-lope were having a race.

Make an x-t graph of the motion diagram.

Since the arrows for the rabbit are 4 times longer than those of the tortoise, the rabbit runs four times faster than

the tortoise.

Dot AlignmentWhat does it mean when 2 dots line up in the same position on the x axis?

Dot AlignmentIt means that the Jackalope reached that position after one time interval, and the tortoise reached the same position after 4 time intervals have passed.

1) Starting Position (Initial Position) 2) Ending Position (Final Position) 3) Distance Traveled 4) Number of Intervals (seconds, min., hours) 5) Number of Beats (metronome) 6) Velocity or Speed Comparison 7) Direction of Motion

Written descriptions of Motion Diagrams include some or all of the following:

What info does this diagram give us?

Give a Written Description

What information can we get from this this Diagram?

Give a Written Description

What info does this diagram give us?

Give a Written Description

-50 meters 30 m0

What info does this diagram give us?

Give a Verbal Description

Compare the Motion of A & Bwith a written description and a

Motion Diagram

A.

B.

30 meters

25 meters

Brad’s Car Mike’s Car

a) Brad and Mike decide to race their cars. They start the race at Mike’s house, which is 200m down the street from Brad’s house. Draw a motion diagram for the two cars when they are both at the starting line, ready to begin the race.

X

Brad’s Car Mike’s Carb) Mike drives his car with a constant speed

of 20 m/s and Brad drives his car at a constant speed of 25 m/s. Draw a motion diagram for both cars when they are moving toward Brad’s house (X).

X

Brad’s Car Mike’s Carc) When Brad reaches his house he does not

wait for Mike, but turns around and drives back to Mike’s house. Draw a motion diagram for the case where Brad drives toward Mike’s house, while Mike is still driving toward Brad’s house.

X

Brad’s Car Mike’s Carc) When Brad reaches his house he does not

wait for Mike, but turns around and drives back to Mike’s house. Draw a motion diagram for the case where Brad drives toward Mike’s house, while Mike is still driving toward Brad’s house.

X

A dog sees a squirrel. From the motion diagram below, tell what movements

the dog’s uses to try to catch the squirrel.

25 meters2015105

Make an x vs t graph of Angela’s Motion

Make an x vs t graph of Angela’s Motion

t (hour)

Draw a motion diagram of the graph below.

• Calculate the slope of the line.

• Make a motion diagram of the graph.

Motion Diagram:

v =3000- 1000

12- 4=250 m / min

250m

min

60 min

1 hour

1 km

1000 m=15 km / h

Draw a motion diagram for these two objects (A & B).