Name: ____________________________
Date:_____________________
Group Members: __________________________________________________________
1.6B Newton’s 3rd Law Balloon Racing
What Do You Think?
• Pretend that you have just met somebody who has never jumped before, let’s call him
Coach Gal.
What instructions could you provide Coach Gal to get him to jump up (that is, which way
do you apply the force when you push with your feet)? _____________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
A Day at the Races
In this experiment you will create a balloon rocket! You will figure out how to shoot the
balloon from the back of the classroom and hit the whiteboard with it at the front of the
room. You will do this using a fishing line as a track for the balloon to follow. First the
teacher will do it as a demo.
Teacher Demo Questions
1. If the front of the room is north and the back is south, which way did the balloon
move? _________________________
2. The balloon didn’t just move it accelerated. How do we know the balloon accelerated?
__________________________________________________________________
3. In what direction did the balloon accelerate? _______________________________
4. How do you know it accelerated in that direction? (Don’t say it is because that is the
direction it moved!!!) __________________________________________________
__________________________________________________________________
5. You know from Newton’s 2nd law that it takes an outside unbalanced force to
accelerate an object like a balloon, what was the force from? ___________________
6. What direction was the force from the air onto the balloon? ____________________
7. We learned from our “Bang Up Job” lab that if the air applied a force onto the
balloon, the balloon must have applies an equal in magnitude force onto the air.
The teacher will now fill the balloon with smoke so you can see the air move. What
direction did the air move? ________________ Which direction did it accelerate?
____________. In what direction was the force of the balloon in the air? _________
8. What can you conclude from this example about the direction of the force on the
balloon as compared to the direction on the force on the air? ___________________
__________________________________________________________________
9. The teacher will now help you create your first action reaction force pair.
a. Action Force: __________________________________________________
b. Reaction force: _________________________________________________
Materials



balloons (one for each team)
plastic straws (one for each team)
tape (cellophane or masking)



fishing line, 10 meters in length
a measuring tape
a stopwatch
For You to Do
1. Split into your groups.
2. Attach one end of the fishing line to the whiteboard with
tape. Have one teammate hold the other end of the fishing
line so that it is taut and roughly horizontal. The line must be held steady and may not be
moved up or down during the experiment.
3. Have one teammate blow up a balloon and hold it shut with his or her fingers. Have
another teammate tape the straw along the side of the balloon. Thread the fishing line
through the straw and hold the balloon at the far end of the line.
4. Race time. First balloon to the wall wins a prize.
Additional Calculations
5. Let’s assume the balloon had a constant acceleration during its flight to the wall. That
means there was also a constant force pushing the balloon, let’s calculate that force. This
gets a bit tricky!!
6. Fill in the table below
Time =
Displacement=
Initial Velocity=
Acceleration =
Mass=
Force=
7. We first need to find the acceleration using the formula d = v1t+ ½ at2. Your teacher will
walk you through this.
8. Now it is time to use Newton’s 2nd law f=ma to solve for the force.
9. Discuss the results with the class. Is there a relationship between the winners of the race
and the group with the greatest force? What is that relationship? _____________________
________________________________________________________________________
________________________________________________________________________
For You to Do-Part 2:
A volunteer will sit on the blue cart. Without touching anything other than the cart and
(whatever they with him) the student will need to move 4 meters across the room
10. Why can’t the student move across the room? _________________________________
11. What is needed for an object to accelerate? ___________________________________
12. The student is given the massive basketball, how can the student use the basketball to
move 4 meters? ___________________________________________________________
________________________________________________________________________
13. Why does throwing the basketball in the opposite direction you need to move work? ___
14. Write an action reaction force pair for this scenario, you apply a force of 50N to the east.
Action:_________________________________________________________________
Reaction:________________________________________________________________
15. Would it be possible to start walking or running on an extremely slippery skating rink
when wearing ordinary shoes? Discuss why or why not in terms of forces. ______________
________________________________________________________________________
________________________________________________________________________
Newton’s Third Law of Motion
Newton’s Third Law of Motion can be stated by the following points:
 Forces always come in pairs (in two’s).
 Each of these two forces always act on different objects
 The amount of the force acting on one object is always the same exact amount
of force acting on the other object.
 The direction of the force acting on one object is always the opposite direction
of the force acting on the other.
All of the above together: For every force there is an equal (in amount) and opposite (in
direction) force.
To better understand the science behind Newton’s Three Laws of Motion you are going to
watch a Bill Nye video on energy.
 Break up into groups of two to four.
 Get an iPad or computer.
 Search “youtube” for Bill Nye on Motion.
 As your group is watching the video complete the worksheet on the following
page.
Three things I knew about Newton’s laws before watching this video were:
1. _____________________________________________________________
2. _____________________________________________________________
3. _____________________________________________________________
Three things I didn’t know about Newton’s laws but I now know are:
1. _____________________________________________________________
2. _____________________________________________________________
3. _____________________________________________________________
1. Everything that exists in the universe is in _________________.
2. To figure out motion, you need to know if you are pushing things or if things are
_____________ you.
3. The air scooter does not move until Bill ____________________ it.
4. If something is _______________, it stays at rest until an outside unbalanced force acts
upon it.
6. Whether an object is moving or staying still, it has (motion / inertia).
7. Things (can be / cannot be) moved if it is pushed or pulled.
8. Newton’s ___________ law of motion states that an object at rest stays at rest and an
object in motion stays in motion until acted on by an outside force.
9. Newton’s third law of motion states that for every action force there is an equal and
opposite ___________.
10. The scale is measuring the pull of the Earth’s __________________ on the apple.
11. When the plane pulls up the scale reads __________________ because the plane is
pulling the apple against gravity.
12. In space the laws of motion (do / do not) apply.
13. The tablecloth couldn’t move objects because it was moving to _____________ to
affect their inertia.
14. The solar system (does / does not) move.
15. Even if we do not feel it we are all moving (very slow / pretty fast).
Unit 1.6: Newton's Third Law Reflection Questions
1. What is the action and reaction force pair when I jump off the skate board?
Action______________________________________________________________
Reaction____________________________________________________________
2. How does the force acting on me compare to the force acting on the skate board? ______
Why? ___________________________________________________________________
________________________________________________________________________
3. How does my acceleration compare to the acceleration of the skate board? ___________
Why? ___________________________________________________________________
________________________________________________________________________
4. Explain how this example obeys Newton’s first law of inertia. _____________________
________________________________________________________________________
________________________________________________________________________
5. What action-reaction forces are involved when a rocket engine fires?
Action__________________________________________________________________
Reaction________________________________________________________________
6. Why doesn't a rocket need air to push on? ____________________________________
_______________________________________________________________________
7. A book sits on a table not moving. Since the book and table don’t move do they still
make an action reaction force pair? _________________ Why ______________________
_______________________________________________________________________
7. If an asteroid exploded which piece would you rather get
hit by? ______________
Why? __________________________________________
_______________________________________________
_______________________________________________
_______________________________________________