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Cover
Table of Contents
Table of Contents
Newton’s First Law of Motion Title Page
Newton’s First Law Teacher Demo
Key Vocabulary
Activity 1: Inertia – A Body at Rest
Activity 1 Teacher Notes
Activity 2: Inertia – A Body in Motion
9 Activity 2 Extension and Teacher Notes
10 Activity 3: And They’re Off!
11 Activity 3 Extension and Teacher Notes
12 Activity 4: Rock and Roll?
13 Activity 4 Teacher Notes
14 Activity 5: Inertia and Unbalanced Forces
15 Post-Activity Assessment Questions
16 Newton’s Second Law of Motion Title Page
17 Newton’s Second Law Teacher Demos
18 Key Vocabulary
19 Activity 6: Collision on the Tracks
20 Activity 6: Collision on the Tracks
21 Activity 6 Teacher Notes
22 Activity 7: Projectile Motion in Two Directions
23 Activity 7 Teacher Demo and Teacher Notes
24 Activity 8: Rollin’ On
25 Post-Activity Assessment Questions
26 Newton’s Third Law of Motion Title Page
27 Newton’s Third Law Teacher Demos
28 Key Vocabulary
29 Activity 9: A Day at the Races
30 Activity 9: A Day at the Races
31 Activity 9 Teacher Notes
32 Activity 10: Reacting to Action
33 Activity 10: Reacting to Action
34 Activity 10 Teacher Notes
35 Post-Activity Assessment Questions
36 Newton’s Law of Gravitation
37 Teacher Demos
38 Key Vocabulary
39 Activity 11: Round and Round They Go
40 Activity 11 Teacher Notes
41 Activity 12: The Gravity of the Situation
42 Post-Activity Assessment Questions
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
o
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 Inertia
 Force
 Speed
 Friction
 Gravity
 Mass

Pendulum
Key Vocabulary
5

Activity # 1: Inertia – A Body at Rest
Purpose: To learn about inertia and bodies at rest.
Materials:
 Book cover or large piece of smooth paper
 Book with hard, glossy cover
 Book with rough or non-glossy cover
 Objects to place on the book cover
Procedure:
1.
Place book cover (or piece of paper) on a flat, smooth surface.
2.
Put book with glossy cover on top of book cover.
3.
Quickly (and in one smooth motion) yank the book cover out from under the book.
4.
Record observations.
5.
Repeat using other book. Record observations.
6.
Repeat using other objects. Record observations.
Data and Observations:
Detailed Observations Object
Glossy-covered book
Non-glossy-covered book
Object(s) 1: __________________
Object(s) 2: __________________
Object(s) 3: __________________
Conclusion:
1.
Does mass have any effect on the experiment? If so, in what way and why?
2.
Does the type of object you had have any effect? If so, in what way and why?
3.
Compare the results of the glossy-covered book and the non-glossy-covered book.
What do you notice?
4.
Explain how this experiment relates to Newton’s First Law of Motion.
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Activity # 1: Inertia – A Body at Rest
Teacher Notes:
 Book should move little, if at all.
 Explanation: o Book does not move because of inertia (a body at rest will stay at rest unless acted on by an outside force). o Objects move less when friction is reduced.
 ACTIVITY TAKES 20-30 MINUTES
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Activity #2: Inertia – A Body in Motion
Purpose: To learn about inertia and bodies in motion.
Background: World War II pilots needed understanding of inertia and motion in order to drop bombs on correct targets.
Materials:
 One tennis ball
 Clearly-marked targets (notebook paper, chalk, tape)
Procedure:
1.
Place a target 10-15 meters away from starting line. Mark the starting line with chalk or tape.
2.
Hold tennis ball and do not let your elbows leave your side as you run and drop the ball.
Do NOT throw the ball. Hold the ball from the sides so you can release your grip as you let it drop.
3.
Have 3 students stand alongside (but slightly back from) the running path to act as observers. One should stand before the target, one at the target, and one just after the target. Their objective is to determine exactly where the runner released the ball and where the ball strikes the ground.
4.
Ask the runner to sprint toward the target as fast as he or she can and try to drop the ball so that it lands on the target.
5.
Next, have the observers make a diagram of where the ball was released and where it landed. Repeat until the ball hits the target.
6.
Repeat steps 4 and 5, using a different runner at a slower speed.
Data and Observations:
Sprinter
Jogger
Conclusion:
1.
Predict what would happen at a walking speed, using the information from your previous trials.
2.
Write a summary of your results. Form conclusions based on the speed of each runner, the location of each ball’s release, and the exact point where each ball landed.
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Activity #2: Inertia – A Body in Motion
Possible Extensions (if time permits)
 Try again using smaller target.
 Drop ball into bucket, decreasing size of bucket with each step.
Teacher Notes:
 When running, students will miss when ball is dropped directly over the target. Ball needs to be dropped before target is reached. Horizontal motion remains unchanged because there is no force in that direction.
 ACTIVITY TAKES ABOUT 40 MINUTES
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Activity # 3: And They’re Off!
Purpose: To learn why Newton’s First Law of Motion is also called the Law of Inertia.
Materials:
 2 identical jars with lids (plastic or glass)
 Flour or sand to fill one jar
 Iron filings or lead pellets to fill the other jar
 2 identical, empty 3-ring binders (at least 2.5” in width)
 Measuring tape
Procedure:
1.
Fill one jar with flour or sand. Pack tightly.
2.
Fill other jar with iron filings or lead pellets. Fill tightly.
3.
Put on lids tightly.
4.
Place binders next to each other on wooden or tile floor. Place each jar on its side and release both from the top of the “ramps” at exactly the same time.
5.
Record how far each jar rolled. Do not measure the binder itself.
6.
Repeat for each surface listed in the table.
Data and Observations:
Trial Surface
1 Wood/Tile
Distance Flour/Sand Jar Traveled Distance Iron/Lead Jar Traveled
2
3
Carpet
Cement
4 Other (_________)
Observations/Trends in Data:
Conclusion:
1.
Did the results depend on whether the jar was filled with flour/sand versus iron/lead? If so, in what way?
2.
Did the results depend on the kind of surface you used? If so, in what way?
3.
What can you say about a body’s tendency to maintain its status quo – its inertia?
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Activity # 3: And They’re Off!
Possible Extension:
 Race an empty jar with one of the filled ones
Teacher Notes:
 Friction causes jars to slow down (Friction: the resistance to motion between two surfaces that touch)
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Activity # 4: Rock and Roll?
Purpose: To understand the concept of rotational inertia.
Background: Rotational Inertia: the inertia of an object rotating on an axis. Rotating objects want to keep spinning. Accounts for the stability of bike riders, navigation on planes, and figure skating.
Materials:
 1 LP record (or cut-foam board or cardboard in a circle with a 12” diameter)
 1 of the following: wooden matchstick, pencil, or headless nail
 String
Procedure:
1.
Tie one end of the string to the middle of a matchstick, pencil, or finishing nail.
2.
Pull the other end of the string through the hole of the LP record (or foam board or cardboard). The match, pencil, or nail should be centered underneath.
3.
Swing the record back and forth like a pendulum. Try to achieve smooth, even motions.
Record observations.
4.
Give the record a spin so that it rotates on top of match, pencil, or nail.
5.
While it’s spinning, try to swing the record again like a pendulum. Record observations.
Data and Observations:
Observations Trial
At Rest
Swinging – Trial 1
Swinging – Trial 2
Spinning & Swinging – Trial 1
Spinning & Swinging – Trial 2
Conclusion:
1.
What do you notice about the angle the record makes with the ground as it swings along its pendulum arc?
2.
How does this relate to Newton’s First Law of Motion?
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Activity # 4: Rock and Roll?
Teacher Notes:
 Once the LP record is set spinning at an angle perpendicular to the string, it will resist any forces (such as gravity) that try to change its angle.
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Activity # 5 – Inertia and Unbalanced Forces
Purpose: To discover the properties of inertia and motion.
Materials:
 Toy car (matchbox or anything that rolls)
 Toy figure of person small enough to sit on car (clay works)
 Meter long piece of cardboard or wood for ramp
 Stack of books to prop up ramp
 An object big and heavy enough to stop car from rolling
Procedure:
1.
Place car on flat, steady surface, like a desktop. Place figure on car. IMPORTANT: Don’t press down so it sticks; just let it rest there.
2.
Observe car. Are there any forces acting on it? What about the figure? Does Newton’s
First Law apply here? Record your observations.
3.
Place one end of board on stack of books to create a ramp. Make sure there is plenty of room at base of ramp for car to roll.
4.
Predict what will happen when the car rolls down the ramp. Record.
5.
Place car and figure at top of ramp. Let go, allowing car and figure to roll down. Record observations.
6.
Place heavy object near bottom of ramp, so that the car will hit it. Predict what will happen and record.
7.
Repeat experiment, making sure figure is placed on car, not stuck to it. Record observations.
8.
Replace the heavy object with a wadded piece of paper, in the car’s path. Predict what will happen and record.
9.
Repeat experiment. Record observations.
Data and Observations:
Prediction Observation
At rest
Down ramp
With book
With paper
Conclusion:
1.
What happened to the book, the car, and the figure? Where your predictions accurate?
2.
Was the situation with the wadded paper different than the book? If so, what specifically was different and why did this change the outcome of the experiment? If nothing changed, why not?
3.
How is this experiment applicable in real life?
4.
If you were a car designer, what kind of feature would you add to a car after performing this experiment? Why?
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Post-Activity Assessment Questions
Newton’s First Law of Motion
ANSWER ALL QUESTIONS USING COMPLETE SENTENCES!
1.
In your own words, describe Newton’s First Law of Motion.
2.
What happens when you are riding in a car with a seatbelt on, and the car starts or stops suddenly? Explain using Newton’s First Law of Motion.
3.
What would happen if you were not wearing your seatbelt? Explain using Newton’s
First Law of Motion.
4.
What relationship does mass have with inertia?
5.
Different materials rest on a table:
A B
12-kg sand 15-kg iron
C
10-kg water
D
2-kg pillow
From greatest to least, rank them by how much they resist being set into motion.
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Teacher Demos:
Demo # 1
 Place an empty cardboard box and 2 or 3 heavy books on a table. Push the empty box across the table. o “Note how much force was required to perform the task.”
 Put one book in the box. Again, push it across the table. o “Was more, less, or the same amount of force required to accomplish the task?”
 Add another book. o Same question
 Explain the experiment using proper vocabulary
Demo # 2

Whirl a yo-yo at end of string in front of you. Ask if yo-yo is changing directions (yes, only motion in a straight line is not changing direction). Movement in a circle is continuously changing direction, therefore it must be undergoing acceleration. Yo-yo is undergoing two motions at once (force of hand going up and down, and side to side).

Discuss other examples of objects that undergo two motions at once (airplane lifting off runway, a baseball hit by a batter). Must experience two forces at once!
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 Force
 Mass
 Acceleration
 Velocity
 Distance
 Time

Deceleration

Gravity

Projectile motion

Parabola

Weight

Trajectory

Speed
Key Vocabulary
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Activity # 6: Collision on the Tracks
Purpose: Investigate the relationship between force, mass, and acceleration.
Materials:

Two identical ball bearings

Two marbles with different masses (similar sizes), each with less mass than the ball bearings

Two tracks, 1 meter each (use meters sticks)

Ruler

Stopwatch

Balance/scale
Procedure:
Set-up:
1.
Determine the mass of each ball bearing and marble. Record in Table 1.
2.
Set up a ramp, 1 meter in length. Use books or a board to incline the ramp at an angle of 5 to
10 degrees.
3.
Starting at the top of the ramp, put marks along the track at 30 and 60 centimeters.
4.
Place the other track at the end of the incline. Make sure there’s a smooth transition where the tracks are joined. Put a book at the end of the last track.
5.
Put one of the ball bearings at the bottom of the inclined track, where it becomes level.
Part 1
6.
Put the marble with the smallest mass at the top of the inclined track. Use the ruler to hold the ball steady.
7.
Before you release the marble, predict what will happen when the marble hits the ball bearing.
Record in Table 2.
8.
Remove the ruler and let the marble roll down the track. Observe what happens when the marble hits the ball bearing. Record in Table 2.
9.
Repeat the experiment, using a stopwatch to measure how long it takes the marble to roll down the track and hit the target ball bearing. Record in Table 3. Use this, along with the marble’s distance traveled, to calculate the acceleration of the marble. (HINT: d = ½ a
 t 2 )
10.
Repeat twice more. First start the marble at the 30 cm mark. Second, start at the 60 cm mark.
Record data and calculate acceleration in Table 3.
11.
Replace the small marble with the larger one. Predict what will happen when this marble hits the ball bearing. Record in Table 2. Let the marble roll down and observe what happens.
Record in Table 2.
12.
Finally, replace the 2 nd ball bearing. Record predictions in Table 2. Let it roll down the ramp.
Record observations in Table 2.
Part 2
13.
Roll the lightest marble from the top of the incline, letting it hit the target ball. Use the stopwatch to record the time it takes the target ball to travel the one-meter to the book.
Record in Table 4. Repeat two more times to determine an average time.
14.
Repeat step 13 with more massive marble and other ball bearing.
15.
Calculate acceleration of bearing and enter results in Table 5.
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Data and Observations:
Table 1
Mass
Marble 1
Marble 2
Ball Bearing 1
Ball Bearing 2
Table 2
Marble 1 vs.
Target Bearing
Marble 2 vs.
Target Bearing
Prediction
Bearing vs.
Target Bearing
Table 3
Average Time (s) Distance Covered
(cm)
Observation
Acceleration
(cm/s/s) d = ½ a
 t 2
Average speed
(cm/s)
Final speed (cm/s)
Avg. speed = d/t Final speed=(2d)/t
Table 4
Marble 1
Marble 2
100
70
40
Trial 1 (s) Trial 2 (s) Trial 3 (s) Average Time (s)
Ball Bearing
Table 5
Force of
Rolling
Ball (N)
F
R
=m
R
 a
R
Average
Target Ball
Roll Time (s)
Table 4
Distance
Target Ball
Moved (cm)
Average Speed of Target Ball
(cm/s)
Avg. speed = d/t
Final Speed of Target Ball
(cm/s)
Final speed=(2d)/t
Acceleration of Target Ball
(cm/s/s) a
T
=F
R
/m
T
Marble 1
Marble 2
100
100
Ball Bearing 100
Conclusion:
1.
Were any of your observations different than what you expected? Why or why not?
2.
What happened to the motion (acceleration) of the target ball as the force from the rolling ball increased (due to the larger masses)?
3.
Using mathematical language, explain the relationship between force and acceleration.
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Activity # 6: Collision on the Tracks
Teacher Notes:
Part 1:
 Calculating Average Speed = Distance Traveled/Average Time
 Calculating Final Speed: v f
= 2d/t
 Calculating acceleration: Two potential ways…I think… o d = ½ a  t 2
 d = distance
 a = acceleration
 t = time o a = (v f
-v i
)/t
 a = acceleration
 v f
= final velocity/speed
 v i
= initial velocity/speed (in this case, equals 0 cm/s)
 t = time

All balls should be as close to same size as possible and NOT hollow!
Part 2 Concepts

In accordance to Newton’s 1 st Law of Motion, the target ball remained at rest until it was acted on by force of impact ball. This force varied depending on mass.

Force is found by F=ma

Force imparted to target ball is found by multiplying mass times acceleration of impact ball.

The larger the force on the impact ball, the larger its acceleration. This is Newton’s 2 nd
Law.
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Activity # 7: Projectile Motion – Motion in Two Directions
Purpose: - To investigate the properties of projectile motion.
Background: Newton’s First Law of Motion tells us that a ball would travel in a straight line forever when thrown unless a force acts on the ball. Gravity is that force. When balls are thrown, they follow a curved path, called a trajectory, which is in the shape of a parabola.
Materials:
 A dart gun with rubber suction-tipped darts
 A measuring tape
 A protractor
 Black marker
 Large piece of cardboard or poster board. Could also use butcher paper.
Procedure:
NOTE: Using the dart gun for any other purposes than what is expressly written in this lab will result in an automatic ZERO and referral to the office!
1.
For each trial, keep the dart gun at the same height above the ground.
2.
Use a protractor to tilt the gun at a given angle. Shoot the gun and measure the horizontal distance traveled. Mark where the dart first hits the ground, not where it finally comes to rest after bouncing. Record data.
3.
Repeat procedure three more times, to average results.
4.
Repeat experiment using 3 more angles. Record results.
Data and Analysis:
Angle Distance Traveled Average Distance
Trial 1 Trial 2 Trial 3 Traveled
Observations
0◦
30◦
60◦
90◦
100
50
Average
Distance
Traveled
0
Distance Traveled
Conclusion:
1.
At what angle should the dart be launched in order for it to travel the farthest horizontal distance? Defend your answer.
2.
Discuss any uncertainties in the experiment.
3.
What could be done to make the dart travel farther?
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Activity # 7: Projectile Motion – Motion in Two Directions
Teacher Demo:
 Monkey and the Hunter o Google it or come see Sandra
Teacher Notes:
 Can make a big protractor: Use 12”x12” paper. Make lines at 0, 15, 30, 45, 60, 75, 90 degrees. Put handle on back to make it easier to use.
 Variable factors – angle
 Constant factors – distance traveled, initial speed, mass, friction (air resistance), initial height
 Angle for best results: 45◦
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Activity #8: Rollin’ On
Purpose: To investigate Newton’s Second Law of Motion
Background: Newton’s First Law tells what happens to an object when no unbalanced forces act on it. Newton’s Second Law tells what happens to an object when an unbalanced force does act on it.
Materials:
 Assorted small spheres
 Straw
 Level Table
Procedure:
Part 1:
1.
Observe the motion of a sphere rolling across a level table. Record detailed observations. Does the sphere accelerate? Why or why not?
Part 2:
2.
Apply a relatively constant force to a sphere by blowing on it through a straw. Record detailed observations.
3.
Repeat using a different size or mass sphere.
Data and Observations:
Detailed Observations
Part 1
Part 2, Sphere 1
Part 2, Sphere 2
Conclusion:
1.
Does the mass of the sphere affect its motion? Why or why not?
2.
While you apply a force to a sphere, what happens to its motion?
3.
When you stop applying the force, what does the sphere do?
4.
Are spheres of different masses affected differently by the same force? Explain.
5.
If a force is applied to an object, two factors affect its motion. What are they and how do they affect the acceleration?
6.
Is it possible for an object with a large mass to have the same acceleration as an object with a small mass? Explain.
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Post-Activity Assessment Questions
Newton’s Second Law of Motion
1.
In your own words, describe Newton’s Second Law of Motion.
2.
What is the upward acceleration of a helicopter with a mass of 5000-kg if a force of
10,000-N acts on it in an upward direction?
3.
Give two real life examples of Newton’s Second Law of Motion.
4.
What produces acceleration?
5.
If the force acting on a sliding block is tripled, what happens to the acceleration?
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Teacher Demos:

Remind students a force is necessary to start something moving when at rest, to change direction, or to change speed.
1.
Throw a ball (baseball, tennis ball) straight up and catch it as it comes down) a.
“What force caused this ball’s direction to change?” i.
Gravity b.
Discuss: If ball is hit with bat, ball changes direction. Name all the forces involved.
2.
Gather a selection of balls, roughly the same size, but very different masses (small beach ball and basketball; softball and whiffle ball)
Part 1 a.
“Newton’s Second Law says you need to apply a greater force on the basketball than the beach ball to have them travel the same distance.” b.
“Newton’s Third Law tells you to expect the basketball to exert a larger force on your foot than the beach ball would if you kicked it.”
Part 2 c.
Have students take turns dropping softball at least 1 meter into hand of another student. Next have them drop the whiffle ball from the same height.
“Which ball required their hand to exert the most force to stop the fall?”
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 Force
 Action
 Reaction
 Height
 Buoyancy
Key Vocabulary
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Activity # 9: A Day at the Races
Purpose: To investigate action-reaction relationships
Background: Early in the 20 th century, the physicist Robert Goddard proposed that rockets would someday be sent to the moon. He met strong opposition from people who thought that such a feat was impossible. They though that a rocket could not work unless it had air to push against.
Materials:
 Balloons (various sizes and shapes)
 Paper clips
 Guide wires (string or fishing line)
 Tape

Straws
Procedure:
Mission 1: Construct a balloon rocket system that will travel across the room.
1.
Set up a guide string from one end of the room to the other. Anchor only one side of the string; leave the other side open so that a straw can be added or removed.
2.
Choose a balloon. Note the shape and size of the balloon. Use a drinking straw; cut the straw to the desired length. Record length.
3.
Inflate balloon (do not tie off!). Use tape to attach the balloon to the straw.
4.
Put the string through the straw and hold the string so it is not sagging. Sketch your setup (accurately!).
5.
Release the end of the balloon. Record observations.
6.
Repeat experiment, but this time change the angle of the rear of the balloon so that it is
45

from the guide line. Describe and record how the rocket system behaves.
7.
Repeat once more, this time with the rear of the balloon at 90

to the guide string.
Observe and record.
Mission 2: Construct a rocket system that can go across the room and then come back (Hint:
Try two tanks).
8.
You are on your own. Be creative. This can be done, but is challenging. It does not need to travel the entire length of the string. Your mission will be considered a success if it travels forward and then at least 3 meters back towards the starting point.
9.
Keep DETAILED notes of each of your tests and progress. You will be graded on your efforts and documentation. You should have diagrams and results of each trial of this mission.
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Data and Observations:
Mission 1:
Balloon Size:
Balloon Shape:
Straw Length:
Sketch of Set-Up:
Angle of
Balloon
0

45

90 
Mission 2:
Balloon #2 Size:
Balloon #2 Shape:
Straw #2 Length:
Trial
1
Sketch
Detailed Observations
Results
2
Keep
Going….
Conclusion:
1.
In Mission 1, you were asked to change the angle of the tank. Explain what happened as the angle changed.
2.
If you changed the length or position of the straw, explain how this affected the outcome of the launch.
3.
Discuss your overall success and failures in Mission 2. What part of your design worked and what did not?
4.
What would you change in your design? Why?
5.
How is Newton’s Third Law of Motion demonstrated by this activity?
6.
Draw pictures, using labeled arrows, to show the action and reaction forces acting on the inside of the balloon before it was released and after it was released.
30

Activity # 9: A Day at the Races
Teacher Notes:
 The air inside the balloon rocket pushes on the rocket, sending it forward. At the same time, the balloon rocket is pushing back on the air inside it (which accounts for the air coming out the back).
 The air outside the balloon pushes on the wall of the balloon, forcing out the air inside the balloon, which is why the balloon moves.
 Most students will not succeed at Mission 2. Grade them on their notes, diagrams, and detailed observations. Stress the importance of this!
31

Activity # 10: Reacting to Action
Purpose: To relate everyday forces to Newton’s Third Law of Motion.
Materials:
 Experiment 1 o Rubber Ball
 Experiment 2 o Two doughnut magnets (similar polarity) o Small plastic toy car o 10 cm of thread o Tape or glue
 Experiment 3 o Wooden block o Bucket of water
Procedure:
NOTE: Make detailed observations as you go!
Experiment 1:
1.
Drop a rubber ball from a height of 1 meter. Catch it when it bounces back up to its maximum height. Record observations in terms of Newton’s Third Law of Motion.
Repeat twice.
Experiment 2:
2.
With tape or glue, attach a doughnut magnet to the back of a small plastic car.
3.
Slowly bring the other magnet close to the back of the vehicle until the vehicle starts to roll forward.
4.
Quickly pull away the magnet in your hand and let the car roll to a stop. Record observations.
5.
Suspend a magnet from a 10 cm length thread.
6.
Hold the end of the thread and bring the hanging magnet toward the back of the vehicle. Record observations.
Experiment 3:
7.
Place a wooden block in a bucket of water so that it floats.
8.
Push the block down into the water and release it. Record observations.
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Data and Observations:
Experiment 1 Detailed Observations
Trial 1
Trial 2
Trial 3
Detailed Observations Experiment 2
Holding magnet
Hanging magnet
Experiment 3
Wooden Block
Detailed Observations
Conclusion:
Experiment 1:
1.
Name the force that caused the ball to start moving.
2.
What must have happened in order for the ball to bounce back to your hand?
3.
After the ball bounces and starts to move upward, what happens to its motion? Why?
Experiment 2:
4.
After your first trial, what force made the car move? What force makes it stop?
5.
Describe all the action/reaction pairs in this case. Draw a diagram to illustrate them.
6.
Describe what happened after your second trail.
7.
How does this experiment relate to Newton’s Third Law of Motion?
Experiment 3:
8.
Describe WHY you got the results you did.
9.
What do you notice if you push the block down to greater and greater depths in the bucket? Explain this in terms of forces.
33

Activity # 10: Reacting to Action
Teacher Notes:
Experiment 1
 Gravity causes ball to move toward ground.
 Floor exerts a force on the ball to change its direction of motion
 As it travels upward, it slows down because the force of gravity is acting in the direction opposite its motion.
 “The floor exerts an equal and opposite force on the falling ball, so it stops the fall of the ball and then provides an upward acceleration to the ball.”
Experiment 2
 Magnetism is a force that “acts at a distance,” like gravity.

Hand pushes magnet forward. Magnetic force between magnets cause toy to move.

Once magnetic force is removed, the car would continue to move in a straight line at a constant speed indefinitely (Newton’s 1 st Law), but instead slows down (decelerates).

To decelerate, a force must be applied (2 nd Law). Friction of tires on table and air on vehicle.

In second part, the magnet on the thread will be pushed backward. The car may move a little or not at all.
Experiment 3:

Buoyant force causes the block in bucket to rise to top and float.

Pressure of liquid increases with depth.

Upward force of the water on the bottom of the object is greater than the downward force of the water on the top of the object. Objects only sink if their weight is larger than the net upward force of the water.
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Post-Activity Assessment Questions
Newton’s Third Law of Motion
1.
In your own words, explain Newton’s Third Law of Motion.
2.
Compare and contrast action and reaction forces.
3.
Can an action force exist without a reaction force?
4.
When you walk on a floor, what pushes you along?
5.
When you rub your hands together, can you push harder on one hand than the other?
6.
If you walk on a log that is floating in the water, the log moves backward. Why?
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2
1
2
2
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2
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 Gravity
 Mass
 Force
 Acceleration
 Trajectory
 Speed

Weight

Radius
Key Vocabulary
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Activity #11: Round & Round They Go
Purpose: To determine the factors involved in an orbital period of the outer planets.
Background: You know the planets orbit the sun. The outer planets take much longer to orbit than the inner planets.
Materials:
 1 sturdy plastic drinking straw, cut in half
 String,18”-24” long
 2 rubber washers or stoppers
Procedure:
1.
Tie one end of the string to one of the washers. Next run the string through the straw and tie it to the other washer.
2.
Make sure you have lots of room around you
3.
Hold the straw and washer assembly upright and pull the string upward until the straw rests against the washer.
4.
Hold the straw with one hand and fully extend your arm out in front of you.
5.
Rapidly rotating your wrist, spin the string-washer assembly until the string is fully extended. Continue spinning at steady rate.
6.
Use your other hand to slowly pull down on the bottom washer
7.
Record observation.
Data & Observation:
Conclusion:
1.
What do you notice about the speed at which the spinning washer is traveling as the string is shortened?
2.
What does the exercise have to do with the planets orbiting the sun?
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Activity # 11: Round and Round They Go
Teacher note:
 Students need to spin waster at quicker rate, steady rate. Keep spinning as the pull 2 nd washer, until point the spinning becomes self-sustaining.
 Remind them to pull string slowly enough for the washer to make complete orbits at each radius before pulling more string.
 Planets farthest from the sun have longer path and move more slowly around the sun than planets closer to sun.
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Activity #12: The Gravity of the Situation
Purpose: To use the equation in Newton’s Law of Gravity.
Background: Mass is a measure of matter, measured in kilograms (1kg = 2.2 lbs). Weight is the force exerted on a mass of a body by a gravitational field, measured in Newton’s.
Materials:
 Calculator
Procedure:
1.
Use the equation for acceleration and the values for the masses and radii of the planets listed in the table.
2.
Complete the third column of the table with the value for the surface gravitational acceleration for each planet (and the moon). g = GM
R 2 g = acceleration due to gravity (m/s 2 ); G = 6.672 x 10 -11 Nm 2 /kg 2 ; M = mass (kg); R = radius (m)
3.
Compare the other planets’ gravity to that of Earth by dividing the gravity you got for the other planet by the Earth’s gravity.
4.
Calculate your weight on each planet (make sure you have converted your mass to kilograms).
W = mg
W = weight (N); m = mass (kg); g = acceleration due to gravity (m/s 2 )
Data:
Acceleration compared to Earth
Your Weight
(N)
Planet Name Mass (kg) Radius (m) Acceleration
(m/s 2 )
Mercury 3.3 x 10 23 2.4 x 10 6
Venus 4.9 x 10 24 6.1 x 10 6
Earth 9.8 m/s 2
Moon
Mars
6.0 x 10 24 6.4 x 10 4
7.4 x 10 22 1.7 x 10 6
6.4 x 10 23 3.4 x 10 6
Jupiter
Saturn
Pluto
1.9 x 10 27 7.1 x 10 7
5.7 x 10 26 6.0 x 10 7
Uranus 8.7 x 10 25 2.6 x 10 7
Neptune 1.0 x 10 26 2.5 x 10 7
1.3 x 10 22 1.2 x 10 6
Conversion of your mass from pounds to kilograms:
Conclusion:
1. What is the difference between mass and weight?
1
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Post-Activity Assessment Questions
Newton’s Law of Gravitation
1.
In your own words, describe Newton’s Law of Gravitation.
2.
Why doesn’t a heavy object accelerate more than a light object when both are free falling?
3.
What is the weight of a 3-kg brick (on Earth)? Show your work.
4.
What is the mass of an automobile that has a weight of 18,000-N (on Earth)? Show your work.
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