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Dr. M. H. Suckley & Mr. P. A. Klozik Email: MAP_at_ScienceScene.com http://www.ScienceScene.com (The MAPs Co.) – PowerPoint PPT presentation

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Title: http://www.ScienceScene.com (The MAPs Co.)


1
To the MAPs Team's Presentation of Motion
Dr. M. H. Suckley Mr. P. A. Klozik Email
MAP_at_ScienceScene.com
http//www.ScienceScene.com
(The MAPs Co.)
2
Motion
3
Motion
I. Introduction II. Newtons First Law III.
Newtons Second Law IV. Newtons Third Law
4
Motion
I. Introduction . . . . . . . . . . . . . . .
. . . . . . . . . . . 3 II. Newtons First Law
. . . . . . . . . . . . . . . . . . . . 4
A. Motion 1. Measuring the
Velocity of Various Objects . . . . . 6
2. Observing Motion of a Toy Car. . . . . .
. . . . . . . . 5 B. Inertia
1. Fundamentals . . . . . . . . . . . . . . . .
. . . . . . . 9 2. Using Your Marbles
. . . . . . . . . . . . . . . . . . . 10
3. FUN With Inertia . . . . . . . . . . . . .
. . . . . . . . 10
5
Motion
III. Newtons Second Law . . . . . . . . . . . .
. . . . . . . 11 A. Acceleration (change in
velocity) 1. Observing Acceleration
. . . . . . . . . . . . . . . . . . .12
2. Acceleration A More Complete Picture . . .
. . . . . 13 B. Fundamentals of Force
1. Observing Forces (using the Gizmo) . .
. . . . . . . 14 2. Finding The
Forces . . . . . . . . . . . . . . . . . . . . .
. 15 3. Types of Force. . . . . . . .
. . . . . . . . . . . . . . . . . . 24
4. Forces in a Collision . . . . . . . . . . . .
. . . . . . . . . 26 5. The Falling
Cup . . . . . . . . . . . . . . . . . . . . . .
. . 27 C. The Affect of Mass on Acceleration
. . . . . . 28
6
Motion
IV. Newtons Third Law . . . . . . . . . . . .
. . . . . 29 A. Equal and Opposite . . .
. . . . . . . . . . . . . . . .30 B. Equal
and Opposite Another Look . . . . . . . . . 31
C. Making Formulas Out of Words . . . . . . .
. . . . . 33
7
(No Transcript)
8
Thank You!
We Had A Great Time
9
Michigan Benchmarks for Motion
Prerequisite Skill
  • Describe or compare motions of common objects in
    terms of speed and direction.
  • Key concepts Words--east, west, north,
    south, right, left, up, down. Speed words--fast,
    slow, faster, slower.
  • Real- world contexts Motions of familiar
    objects in two dimensions, including rolling or
    thrown balls, wheeled vehicles, sliding objects.

forces
  • Describe how forces (pushes or pulls) are needed
    to speed up, slow down, stop, or change the
    direction of a moving object.
  • Key concepts Changes in motion--speeding
    up, slowing down, turning. Common forces--push,
    pull, friction, gravity. Size of change is
    related to strength of push or pull.
  • Real- world contexts Playing ball, moving
    chairs, sliding objects.

V d / t
  • Qualitative describe and compare motion in two
    dimensions.
  • Key concepts Two- dimensional motion--up,
    down, curved path. Speed, direction, change in
    speed, change in direction.
  • Real- world contexts Objects in motion,
    such as thrown balls, roller coasters, cars on
    hills, airplanes.

F m x a
4. Relate motion of objects to unbalanced and
balanced forces in two dimensions. Key concepts
Changes in motion and common forces--speeding up,
slowing down, turning, push, pull, friction,
gravity, magnets. Constant motion and balanced
forces. Additional forces--attraction, repulsion,
action/ reaction pair (interaction force),
buoyant force. Size of change is related to
strength of unbalanced force and mass of object.
Real- world contexts Changing the
direction--changing the direction of a billiard
ball, bus turning a corner changing the
speed--car speeding up, a rolling ball slowing
down, magnets changing the motion of objects,
walking, swimming, jumping, rocket motion,
objects resting on a table, tug- of- war.
Future Unit
5. Design strategies for moving objects by
application of forces, including the use of
simple machines. Real- world contexts Changing
the direction--changing the direction of a
billiard ball, bus turning a corner changing the
speed--car speeding up, a rolling ball slowing
down, magnets changing the motion of objects,
walking, swimming, jumping, rocket motion,
objects resting on a table, tug- of- war.

1
11
10
Naïve ideas
  • 1. The distance an object travels and its
    displacement are always the same.
  • 2. An objects speed and velocity are always the
    same.
  • 3. An object having inertia is always at rest.
  • 4. Acceleration is always in a straight line.
  • 5. Acceleration means that an object is speeding
    up.
  • 6. The numerical value of acceleration is always
    a positive number.

6
0
11
Newtons First Law
  • An object stays at rest or continues to move in
    a straight line at a constant speed unless acted
    on by a force.
  • V d / t

12
Time Distance
Observing Motion
Velocity Meters/sec
Distance meters
Average Sec.
Trial 3 Sec.
Trial 2 Sec.
Trial 1 Sec.

1.14
.500
0.44
0.43
0.44
0.43
1.09
.350
0.32
0.32
0.32
0.31
Equipment Set-Up
0
6
13
2
14
1
15
0
16
Measuring The Velocity of Various Objects
Object Distance Distance Time Speed Speed Average Distance Time Speed Average
1. Toy Cars Battery Powered Car Battery Powered Car Battery Powered Car Battery Powered Car Battery Powered Car Battery Powered Car Pull Back Car Pull Back Car Pull Back Car Pull Back Car
1. Toy Cars Trial 1                                                      
1. Toy Cars Trial 2                                                      
1. Toy Cars Trial 3                                                      
2. Flowing Water 400-ml. Beaker 400-ml. Beaker 400-ml. Beaker 400-ml. Beaker 400-ml. Beaker 400-ml. Beaker 250-ml. Beaker 250-ml. Beaker 250-ml. Beaker 250-ml. Beaker
2. Flowing Water Trial 1                                                      
2. Flowing Water Trial 2                                                      
2. Flowing Water Trial 3                                                      
3. Clock Hands Wall Clock Wall Clock Wall Clock Wall Clock Wall Clock Wall Clock Wrist Watch With Second Hand Wrist Watch With Second Hand Wrist Watch With Second Hand Wrist Watch With Second Hand
3. Clock Hands Trial 1                                                      
3. Clock Hands Trial 2                                                      
4. Bouncing Ball Tennis Ball Tennis Ball Tennis Ball Tennis Ball Tennis Ball Tennis Ball Super Ball Super Ball Super Ball Super Ball
4. Bouncing Ball Trial 1                                                      
4. Bouncing Ball Trial 2                                                      
4. Bouncing Ball Trial 3                                                      
5. Sound Speed of Sound Speed of Sound Speed of Sound Speed of Sound Speed of Sound Speed of Sound
5. Sound Trial 1                              
5. Sound Trial 2                              
5. Sound Trial 2                              
17
Time
  • The interval between two events.

1
18
Distance
  • The interval between two objects.

19
Measuring the Filling Speed of Water
  • a. Turn the water on at a moderate rate. Keep
    this flow constant for both beakers.
  • b. Fill the 400 ml. beaker with any amount
    (approximately one fourth of the beaker) of
    water, while timing (t).
  • c. Mark the top of the water, and measure its
    distance in meters from the bottom of the beaker
    to the top of the water.
  • d. Repeat this for two additional readings.
  • e. Compute the distance (x) the water level rose
    using
  • x1 L1 - L0
  • x2 L2 - L1
  • x3 L3 - L2
  • f. Compute the velocity of water flow using v
    x / t.
  • g. Repeat this for two additional readings.
  • h. Obtain average velocity of the water flow.
  • i. Repeat for a 250 ml beaker.

3
20
Measuring The Speed Of A Clocks Second Hand
a. Select a wall clock with a second hand.
b. As the tip of the second hand rotates around
the center of the clock traveling a certain
distance (x), in a given time (t).
d. Compute the distance traveled by the outer
point of the second. e. Compute the speed using
v x / t

Note
  • The tip of the second hand moves in a circle. In
    order to find the distance traveled, we must find
    the circumference of that circle. To determine
    the circumference, we must measure the radius (r)
    of the circle in meters. The radius is the
    distance between the center of the clock, and the
    tip of the second hand. Double that figure to
    obtain the diameter, and multiply that result by
    pi (3.14).
  • 2) The total distance traveled would be the
    number of full revolutions (N) multiplied by the
    distance traveled or x (N) x 2r x 3.14. Call
    this distance x, and record.

21
Measuring The Velocity Of A Bouncing Ball.
  • The total distance (x) that the ball traveled is
    equal to the sum of the heights x1, x2 and x3.
    The initial height is x1, the final height is
    (x3) and the average of x1 and x3 is x2. The
    total distance (x) that the ball traveled is
    equal to the sum of the heights (x x1 x2 x2
    x3). The heights are most easily measured by
    bouncing the ball near a wall, using the brick
    divisions to help in the measurement of the
    height of the bounce.
  • b. The time (t) taken for the ball to make two
    bounces would be measured from the starting point
    (the release point), to the end point (the top of
    the second bounce).
  • c. Compute the average speed using v x / t.
  • Collect three sets of data and calculate the
    average velocity.
  • e. Repeat for the second ball

x1
x2
x2
x3
Total Distance (x) x1 x2 x2 x3
1
Simulation
22
Speed Of Sound
BANG!

Observers start their stopwatches when they see
the flash of light created at the same instant a
loud sound occurs. They stop their stopwatches
when they hear the sound. Using their data
calculate the speed of sound.

Velocity
Time
Distance
Trial
1.01-sec.
331.2-m
1
1.06-sec.
331.2-m
2
1.08-sec.
331.2-m
3
1. Experimental Speed of Sound distance /
time 2. Theoretical Speed of Sound 330 m/sec.
(.6 m/sec. x Temperature) 3.
Temperature 23.1 ºC 4. Calculate Percent of
Error
2
23
Inertia

2
Applying Large Force
Applying Small Force
24
What is Inertia?
  • Answer
  • The tendency of matter to remain at rest if
    it is at rest or, if moving, the tendency to keep
    moving in the same direction unless acted upon by
    some outside force.

2
1
25
Newton's First Law - Inertia
Objects at rest remain at rest. Objects at rest remain at rest.
                                                                                                            
A lot of inertia! Very little inertia.
Since the train is so huge, it is difficult to move the train from rest. Since the baby carriage is so small, it is very easy to move from rest.
Objects in motion remain in motion in a straight line (unless acted upon by an outside force). Objects in motion remain in motion in a straight line (unless acted upon by an outside force).
                                                                                                                 
A lot of inertia! Very little inertia
Since the train is so huge, it is difficult to stop it once it is moving. Since the soccer ball is so small, it is very easy to stop it once it is moving.
0
26
Inertia - Using Your Marbles
27
Newtons First Law
2
4
28
Newtons First Law
3
29
Newtons First Law
2
30
Newtons First Law
1
Click for Inertia Movie
31
Newtons First Law
0
32
Newtons Second Law
  • When a force acts on a moving object, it will
    accelerate in the direction of the force
    dependent on its mass and the force.
  • F m x a

33
Observing Acceleration - of a Toy Car
0.150-m t1? t2 (t2- t1)
0.500-m t0? t2
0.350-m t0? t1
0.11
0.43
0.32
First time trial
0.13
0.44
0.31
Second time trial
0.11
0.43
0.32
Third time trial
0.12
0.44
0.32
(4) Average Time
V2 1.25-m/s
V1 1.09-m/s
(5) Average velocity v d / t
Position B TB (t2 t1) / 2 0.38-sec
Position A TA t1/2 0.16-sec
6) Time (when average velocity occurred)
0.16-m/s
(6) ?v change in adjacent velocity ?v
v2 v1 
0.22-sec
(7) ?T change in time between adjacent
velocity ?t TB TA 
.73-m/s/s .73-m/s2
(8) a acceleration between points a
?v / ?t
13
34
Acceleration A More Complete Picture
Excel Worksheet Push F9 to Reveal Calculations
35
Observing Forces
Bubble Level Accelerometer
Direction of FORCE (movement of the accelerometer
bubble)
Movement of the Car
It remains constant
None
Forward
It moves forward
It moves backward
Backward
It moves towards the center of rotation
Circular
1
8
36
Circular Motion
The following diagram helps to explain the
circular motion of an object. This motion depends
on the objects inertia, straight line direction,
and the force applied by a string pulling the
object towards the center of the circle.
ID
ID
ID Inertia direction
Rx Resultant of Inertia Center Pull
ID
R4
CP Center Pull direction
CP
CP
R3
CP
ID
CP
CP
ID
R1
CP
CP
CP
ID
R2
ID
0
3
ID
37
Understanding Forces
Types of Forces
Pushes and Pulls
2
38
Finding The Forces ActivitiesRead the
description in the handout and identify the
Forces for each activity
1
8
39
Finding The Forces Activities
0
7
40
Types of Forces
  • A force is defined as any push or pull that
    results in accelerating motion
  • Circular - When objects move in circles, a force
    acts with a direction that is toward the center
    of the circle. We call this direction
    CENTRIPETAL
  • Gravitational - All objects attract all other
    objects with a force called gravitational force.
  • Electromagnetic - Electric forces act on objects
    when the object carries a net electric charge or
    a non-uniform distribution of charge. Magnetic
    force is also observed around a moving electric
    charge and act on those charges. Physicists
    believe that all magnetic forces are produced by
    moving charges.
  • Frictional - Frictional forces are often
    classified as sliding, rolling, static and fluid.
  • Sliding and rolling frictional forces result
    when solids in contact pass by each other. Static
    frictional force results when solids are in
    contact, at rest and when a force or forces are
    trying to cause them to move with respect to each
    other. Fluid frictional force results when a
    solid is moving through a gas or a liquid.
  • Normal - Normal means perpendicular to.
    Whenever an object is placed on a surface, a
    force acts normal to the surfaces in contact.
    This causes the supporting surface to sag. Since
    this sagging is slight, it often goes unnoticed.
    However, it is always there and the resulting
    force of the surface attempting to return to its
    original position is perpendicular to the
    surface.
  • Tension - Tension force is the force exerted by a
    string, spring, beam or other object which is
    being stretched compressed. The electric forces
    among the molecules give rise to the force.

Circular Gravitational Electromagnetic Frictional
Normal Tension
7
41
Forces in a Collision
  • The diagram shows a child and an adult pushing on
    each other while holding bathroom scales to
    measure the forces. Predict how they will move.
    Explain your prediction. (Does the answer depend
    on who does the pushing? What if both push at the
    same time?)
  • Which scale will show the biggest number?
  • 3. Suppose the situation was slightly different
    than the illustration. For each situation below,
    predict how the readings on the scales would
    compare with each other. Explain your
    predictions.
  • a. If the adults chair was backed up against a
    wall.
  • b. If the childs chair was backed up against a
    wall.
  • c. If both chairs were backed up against a wall.

42
The Falling Cup
43
The Affect of Mass on Acceleration
Battery
Velocity Meters/sec
Distance meters
Average Sec.
Trial 3 Sec.
Trial 2 Sec.
Trial 1 Sec.
1.14
.500
0.44
0.43
0.44
0.43
Without
0.86
.500
0.58
0.60
0.57
0.56
With
8
44
Newtons Third Law
  • Every Action Has An Equal
  • And
  • Opposite Reaction.
  • f1 f2

3
45
Newtons Third Law
2
46
Newtons Third Law
1
47
Newtons Third Law
0
48
Equal and Opposite - Newtons Third Law

Slippery Plastic
1. Crumple the plastic until it looks very
wrinkled 2. Place the slippery plastic on a
solid, flat surface. 3. Place the car on top on
the slippery plastic. 4. Start the car and
observe the car and the slippery plastic.
4
49
Equal and Opposite, Another Look
1. Place two soda cans on a flat surface
approximately 25-cm apart. 2. Place the plastic
on top of the soda cans. 3. Place the car on top
on the plastic as shown. 4. Start the car and
carefully observe the car and the plastic.
3
2
50
The Hover CoverBalloon Powered
Materials Scissors, Plastic lid from a cottage
cheese container, Push-pull squirt cap from a
bottle of dishwashing liquid, Glue, Round balloon

Instructions 1. Cut a hole 3/4 inch in diameter
in the center of the plastic lid from the cottage
cheese container. 2. Center the push-pull squirt
cap over the hole and glue it to the lid, with
the lid's writing face up. Use enough glue so
that no air spaces are left between the plastic
surface of the cap and the plastic of the lid.
Let the glue dry completely. 3. Blow up a round
balloon and slip the opening over the opening on
the closed squirt cap. 4. Place the device on a
smooth surface, such as a table top, and lift
the squirt-cap opening so that the air escapes
from the balloon and your space car will glide
effortlessly.
1
51
Newtons Third Law
0
52
The Stopwatch

53
MAKING FORMULAS OUT OF WORDS
Note to make the equation simple we place
in place of the word change
Note The arrow indicates a change in direction
7
54
Thank You!
We Had A Great Time
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