Do the activities in turn.
Fill the bottle with water, with a finger over the hole, and hold it over a sink.
Let the water stream out of the hole. Ask a student to shine the laser through the bottle and into the start of the stream.
The laser light will be reflected from the sides of the inside of the stream, so it stays inside the stream of water even as it curves, so lighting up the water stream. There is a point where the stream curves too steeply for the internal reflection to continue.
Give students pocket lasers, small mirrors, and tape.
Ask them to reflect the laser around the room.
It is more challenging than expected, as a slight change of angle of the mirror will change the direction of the laser dramatically.
Very fun, but very dusty for other objects in the room: clap cornstarch in the air to visualize the laser beams. Students can design a challenge where they have to crawl under and climb over laser beams without touching them.
Fill the fish tank with water (do not try to move after filling).
Add a few drops of milk and swirl around. The milk will only just be visible. It is easy to add too much.
Darken the room.
Ask students to shine their lasers in the tank, observing what happens when it hits the glass at the sides of the tank, as well as the surface of the water.
The lasers will reflect off the glass, and also the surface of the water, which behave like mirrors. Also interesting is that some of the beam reflects back and some does not, so the path of the laser light is split, so with multiple reflections interesting patterns can be made from just one laser beam.
For more experimentation add mirrors under the water for students to move around.
https://www.youtube.com/watch?v=aN1saYRr6z4
Light beams in a tank of water, showing reflection and refraction: https://www.youtube.com/watch?v=2kBOqfS0nmE
A progression of activities that works well (with recommended substitutions):
Pulley free play, for students to understand how pulleys rotate to move rope through them, making the rope move more easily than without a pulley (way less friction). They will also show how a pulley can change the direction of a force. They will get creative with multiple pulleys and make their own systems.
Start adding more pulleys to show how they give a force advantage. Recommend measuring forces with counters, but could also just feel the forces with a desktop system.
End with a dramatic demonstration of how multiple pulley systems lift a heavy load.
Set up the pulley system as shown, first with just one pulley at table height - the rope passes from the weight and through the pulley only.
Feel the force that it takes to pull the weight up.
Then add a pulley to the water bottle. Pass the rope back and forth between the fixed pulley at the top and the moveable pulley at the bottom, so that four rope lengths are holding up the bottle.
Feel the force needed to lift the water bottle, and compare to the single pulley system previously done.
As more lengths of rope are pulling the weight up, the force needed to pull the rope is less. With four ropes pulling up the weight, the force required should be a fourth.
But in exchange, more rope will have to be pulled through (less force over a greater distance, compared to more force over less distance with just one pulley).
Assemble as pictured.
The rod holding the pen, must be able to freely move up and down, but with out any sideways wiggle. I had to hold with my hands to prevent losening.
Pin the paper to the board.
Add the cans in the corners for weight.
Set the board in motion.
Then drop the pen on the board.
Do not touch anything that will impede the free swinging of the board or the motion of the pen arm.
Materials in the chosen activities
Do a selection of activities.
For a States of Matter focus:
Review states of matter.
Draw up a temperature number line and add the state changes in water.
Show dry ice, discuss when it sublimates, and add it to the number line.
Dry ice squealing on a spoon demonstration - the metal speeds up sublimation.
Dry ice in tubs on table groups to observe clouds.
Show students how to make tornados.
End with a lemonade soda drink (add dry ice to lemonade in a pitcher, then sieve before distributing to students for drinking).
Construct the cannon:
Cut a hole on one side of the box (works best if this is about half the diameter of the box).
Cut part of the other side of the box out, and tape a plastic bag over it, so it is a little flexible.
Add a handle to the plastic with tape, so that it can be pulled back and forth.
Add the container of warm water and dry ice to the box.
Once the box fills with dry ice gas, draw back the plastic then move it forwards quickly.
A vortex of gas should emerge from the hole (best seen against a dark background).
Scaled down, individuals can each make their own vortex.
http://www.waynesthisandthat.com/airblasters.html
With no dry ice in the box, a vortex of air is still made, which will travel to move light objects on the other side of the room.
1. Place a nugget of dry ice in an empty aluminum pie pan and press on it with a metal spoon. You should hear squealing or squeaking sounds as the spoon and pan vibrates. This is caused by heat from the spoon and pan warming the carbon dioxide and changing it from solid to gas (sublimation), which then pushes the ice away from the spoon and pan, causing them to vibrate.
2. A nugget of dry ice vibrates on a spoon as it sublimates and the gas escapes under it. Once the dry ice has cooled the spoon down, the vibration stops, and water vapour in the air turns to ice crystals on the cool spoon.
3. Press side of coins into dry ice. The coins flip back and forth. The warm coins heat the dry ice and turn it to gas. The gas escapes in the enclosed space pushing the coin back and forth.