7th Grade Tech
Name:________________________________________ Per:___
LAB: Make your own Hover Craft!
Due Date:___________________________
Make it, Learn it, Teach it! Lab
I promise to respect my school, my teachers, and my friends by not using my
hovercraft or the parts of the hovercraft in an inappropriate way (i.e. blowing up
the balloon in another class, using materials inappropriately). I understand that
if I do, my hovercraft is taken away, I will receive a zero for this assignment.
I also will be respectful and trustworthy when we ride the hovercraft. If I
misbehave, I realize that I will NOT be allowed to participate!!!
Student Signature____________________________________________
Date _____________
Materials
 CD
 Twist top from a drink bottle (like from a sports water bottle)
 or Bottle with Cap ( from a soda bottle)
 Pin to Make Holes for Air flow
 Elmer’s Glue or Hot Glue
 1 Balloon
 1 Sheet of Paper
Learn It!
Read EACH instruction completely before beginning each step!
1. Gather Materials
2. Have Teacher Cut the top off of your bottle. If using a pop-top skip this step.
3. Close the twist bottle top and glue to adhere the bottle top to the CD. Be sure the glue
does not plug the top and that the top lines up with the hole in the center of the CD.
4. Blow up a balloon and twist the neck so that no air can escape. Don’t tie the balloon!
5. Stretch the neck of the twisted balloon over the closed twist top. Then remove your fingers
from pinching the balloon.
6. Place the CD hovercraft on a bench top and push the hovercraft. What do you observe does it move? If so, does it go very far? If not, why not?
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7. Draw a force diagram showing ALL the forces acting on the hovercraft WHILE you are
pushing it with the twist cap closed.
8. With the cap closed and the balloon twisted, does the hovercraft move once you stop
pushing it? Why or why not?
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9. Open the twist top or untwist the balloon all the way to release the air and push the
hovercraft. Does it move now? If so, how far does it move this time?
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10. Blow up the balloon again. Open the balloon to let the air flow and push the hovercraft
gently. Once you stop pushing it and remove your hand, does it keep moving? Why or
why not?
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11. Galileo said that in the absence of friction, there is no force needed to keep an object
going and the object will go on forever. Do you experience that with the hovercraft you
made? Why or why not?
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12. When you release the air in the balloon, it rushes under the CD and lifts it off the table.
a. What force have we eliminated? ____________________
Friction
Air
Gravity
Applied
b. What other force is eliminated when the CD is lifted off the table?
______________
c. What forces are acting on the hovercraft when it is moving while the twist
cap is open and air is flowing? Circle all that apply.
Friction
Air
Gravity
Applied
d. Define Dynamic Equilibrium in your own words:
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Extension
Did you notice that the Balloon was dragging behind on the surface of the table or floor?
Using the piece of paper create a collar to help hold the balloon up and create less friction
and drag for your hovercraft.
NOTE:
The hovercraft will still work without the paper collar, however the balloon tends to flop
sideways and drag along the ground, creating friction.
Retest and see how it works!!!
Answer YES or NO
1. Did the collar help hold the balloon up of the ground. ____________
2. Did your hovercraft move around more freely? _____________
3. Draw a force diagram below for a hovercraft in dynamic equilibrium. Label all the forces
acting on the hovercraft. Do this qualitative. Do not worry about numbers.
4. If you could re-build the hovercraft what materials would you use?
5. If you could redo the Lab, what would you do differently?
Name______________________________________
Period_________ Date________________
Homework
Teach it! A Family Homework Assignment
Review the questions below. Based on what you have learned, teach a parent/guardian
how a hovercraft works! In addition, discuss why the concept of inertia can be
counterintuitive (difficult to understand) for most people. Then have them take this quiz, share
any thoughts, and sign their name.
1. True or False: The balloon provides the air to lift the CD off the table.
2. True or False: The force of friction is eliminated when the CD lifts off the table and
becomes a hovercraft.
3. True or False. When the hovercraft is moving friction-free, the forces are balanced and
is said to be in dynamic equilibrium.
4. True or False: In the absence of friction, there is nothing required to keep an object
moving.
5. Student Reaction to the Make and Take Hovercraft Lab: Was this a good way for you
to learn about friction and air pressure?
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6. Parent / Guardian Reaction to the Make and Take Hovercraft Lab: What is your take
on the benefits of these activities?
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Please below to give permission to your child if they can ride the hocercraft.
Parent/Guardian Signature _________________________________
Date ____________ Circle :Yes or No
Thank you for sharing in this lab experience with your student! Tech is Fun!!!