Port Hope Fall Fair

The port Hope Fall Fair was a blast as usual. My grandson Nick and I arrived at 8:20 am at the Town Park Recreation Center in Port Hope. I found the Cameco tent where we were to set up. Cameco personnel guided us to our Scientists in School (SiS) area and Nick and I began to set up. Cameco joined Scientists in School about three years ago as one of our sponsors. We were grateful to Cameco for providing such a large tent, for the tables to be set up, and to be out of the 6 degrees celcius weather. Afterall, it is only September 14th and it is still Summer.

Nick and I continued to set up as Angela Maclean, another SiS presenter arrived. Angela had a couple of neat hands-on activities related to solar power. Both Angela and I were ready to go for the 9:00 am opening. Sarah Carnegie, a Team Leader with SiS joined us.

Traffic was slow until about 10:20 am. Nick and I were teaching children to build alloon powered hovercrafts using an old cd, a wooden spool, duct tape and a 12" party balloon. It is the easiest thing in the world to make. When all of the pieces are attached, you blow through the hole at the bottom of the cd. The air goes throgh the hole in the spool and inflates the balloon. When the balloon is large enough and pinching the neck of the balloon so air doesn't escape, you place your newly constructed hovercraft on a flat surface, give it a little push and watch it cruise across the table. It's floating on a cusion of air provided by the balloon as the balloon deflates. The hovercrafts function can be described by Sir Isaac Newton's Third Law: "For every action, there's an equal and opposite reaction." Air goes down, action, cd goes up, reaction. The balloons forward mo

vement is based upon Newton's First Law. "every object remains at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force." By giving the balloon a slight push (external force) the balloon at rest begins to move. Grade 6 students who study flight understand Newton's First and Third laws.

Balloon Powered Hovercraft

Balloon Powered Hovercraft

Using the materials listed, make a hovercraft and try to make it travel as far as possible.

Materials:

1 old CD

1 wooden spool

1 12” party balloon

4 pscs 10 cm x 2 cm piece of duct tape

Thin card (if needed)

Construction:

1. Take 1 piece of tape and attach half of it lengthwise to the base of the spool.

2. Centre the spool over the hole of the CD and tape the spool to the CD.

3. Repeat Step 2 with each piece of tape making two strips parallel on opposite sides of the spool and the other 2 parallell at 90 degrees to the first pair so that the base of the spool in securely taped to the cd with no air leaks.

4. Inflate the balloon to stretch it somewhat. Let the air out. Attach it over the wooden spool.



Testing:

1. Inflate the balloon by blowing through the base of the cd. Squeeze the base of the balloon to hold the air in while you inhale before blowing more air into the balloon.

2. Gently push it along a smooth surface.

Question:

How far did it go in cm (m)? (Intent: To demonstrate Newton’s 3rd Law of Action (air coming out of the balloon in a downward motion) and Reaction (the cd moving up in the opposite direction). Newton said that for every action there is an opposite and equal reaction.  The distance the disc travels is related to thrust and friction.

Extension:

1. How can you make the balloon cover a greater distance? (Possible Answers: Use larger balloons, use smoother surfaces, cut a straw the length of the spool and put it inside to make the hole narrower and possibly increase the thrust).

2. How can you prevent the balloon from dragging behind once its air is expended? (Possible Answer: Place a thin card around the neck of the balloon to elevate the upper part of the balloon when the air is expended to prevent it from dragging).

Updated by

Stan Taylor

September, 2012 (originally created September, 1998)

Balloon Hovercraft

I teach a science workshop with Scientists in School called, "Air and Flight." As part of my introduction, I demonstrate Newton's 3rd Law by pushing my Balloon Hovercraft across the students' desks, much to their delight.

Yesterday, I was at the Malvern Town Plaza in Scarborough teaching children who passed by my table how to build balsawood gliders and hovercrafts.

Using the materials listed, make a hovercraft and try to make it travel as far as possible.

Materials:
1 old CD
1 wooden spool (or plastic..the type that once had thread on it)
1 12" party balloon
20 cm x 2 cm piece of duct tape
Thin card (if needed)

Construction:
1. Tear the duct tape into 4 pieces about the same length.
2. Take 1 piece of tape and attach half of it lengthwise to the base of the spool.
3. Centre the spool over the hole of the CD and tape the spool to the CD.
4. Inflate the balloon to stretch it somewhat. Let the air out. Attach it over the wooden spool.

Testing:
1. Inflate the balloon by blowing through the hole at the base of the CD.
2. Gently push the hovercraft along a smooth surface.

How far did it go in cm (m)?

Extension:
1. How can you make the balloon cover a greater distance? (Possible Answers: Use larger balloons, use smoother surfaces, cut a straw the length of the spool and put it inside to make the hole narrower and possibly increase the thrust).
2. How can you prevent the balloon from dragging behind once its air is expended? (Possible Answer: Place a thin card around the neck of the balloon to prevent it from dragging).