Experiment 1: Paper Race

Instructions:

1. Hold a book and the paper at the same height and ask the students to predict which will fall fastest. Drop both to show that the book will fall fastest.
2. Point out that both are made of paper and suggest they should fall at the same rate. Propose repeating the experiment, removing air resistance for the paper. Which will fall faster now?
3. Place the paper on top of the book and drop both together. They should remain together, falling at the same rate.
4. The paper can fall even faster than the book if it experiences less air resistance. Hold the paper a centimeter or two above the book, drop both at the same time, and the paper should catch up to the book during the fall.

Experiment 2: Bernoulli Circus

Instructions:

A – Bernoulli Effect with Paper

1. Hold both pages vertically in front of your mouth. Tell the audience you will blow between the pages and ask them to predict whether they will move further apart, closer together, or not move.
2. When you blow between the pages, they should move together due to the Bernoulli Effect – moving air will have lower pressure than still air, and so the higher atmospheric pressure outside of the pages will push the paper into the lower-pressure moving air in between.

B – Coanda Effect with Balloon

1. Inflate a balloon to roughly 5 cm diameter and tie the end.
2. Hold the straw nearly vertical and blow into it to float the balloon above the straw.
3. The balloon should be able to float several cm above the straw and will often wobble back and forth around the centre of the stream of air.

Experiment 3: Air Vortex

Instructions:

1.  Create a homemade vortex cannon from a cardbox box by cutting a hole in one end, then use the box to send invisible vortices of air across the room.
2. Fixed target – using paper, the vortex can be detected through its interaction with fixed target.  Note – interacting with a fixed target can tell us about the position and energy of the target, but gives no information of the
3. Tracking – have volunteers blow as many bubbles as possible.  Send vortices through the bubbles – it should be possible to see the path of the vortex from its low-energy interaction with the bubbles which do not significantly affect its trajectory.

Experiment 4: Coloured Florescence

Instructions:

1. Ask a few volunteers to make drawings using fluorescent highlighters, instructing one to use only a yellow highlighter.
2. Make sure the room is dark and shine a bright red light on the drawing with yellow only.  The drawing should not appear, because the yellow highlighter only contains a phosphor, but no pigment, so will not interact with red light. The drawing should appear as a blank page.
3. Turn on the blue light and the yellow highlighter appears bright yellow.
4. Fluorescence is the re-emission of light of a lower energy colour. Therefore the fluoresced light must have less energy than the incident light. So blue light has more energy than yellow, which has more energy than red.
5. Observe that yellow will fluoresce weakly under green light (it also blends in with green). This shows that yellow also has less energy than green light.
6. Next, show the multi-coloured drawings under red, blue and green light, to fit the remaining colours in the spectrum.

Experiment 5: Hoop Glider

Instructions:

1. Cut two strips of paper, roughly 2 cm wide, one 20 cm long and the other 30 cm long.
2. Bend each strip to make a loop and tape the loop closed.
3. Tape the loops to each end of a drinking straw – it is now ready to fly!
4. Gently throw the hoop glider – it should smoothly glide through the air.
5. If time and interest permit, this can be turned into an investigation changing variables like diameter of hoop, width of paper, length of straw, etc.