Science is all around us, and it is fantastic! Otago Museum’s science team loves showing children how fun science can be. Here’s a favourite Science Show Offs that you can do with your favourite adult to learn about physics.
Take an effervescent tablet container and make it aerodynamic!
Cut three triangular fins that have a right angle, so that the long edge can be stuck against the tube, while the short bottom edge is flat to the ground. Each triangle should be about 5 cm high and 2 cm wide. Stick the fins to the bottom of the container (not the end with the lid) using sticky tape.
Then make a cone for the other end of the tube. You can make the cone from a circle (about 5 cm in diameter) cut from cardboard. Mark the centre of the circle with a dot. Cut from the edge to the dot. Take the two sides of your cut and bring them together until they overlap, making a cone. Keep making the cone smaller until it fits the top of your tube, like a hat! Fix the seam with tape and then tape the cone onto the enclosed end of the tube (not the end with the lid).
Take one effervescent tablet and break it into four pieces (you will only need one piece for each launch). Put a tablespoon of water into the empty ‘rocket’, put in the piece of the tablet, and quickly put the lid on.
Put your rocket into a large empty container, so that all the fizzy water doesn’t spill everywhere, and get ready for it to launch. Your rocket will zoom upwards like a real spaceship, so be careful of people, pets, and Mum’s best vase! (It takes
10 to 30 seconds for the launch to happen.)
But how does it work?
The chemical reaction of the tablet with water releases carbon dioxide gas, which builds up pressure in the closed tube. When the pressure gets great enough to pop the lid, it pushes down on the ground, which results in an upwards push on the tube, launching the rocket! This is Newton’s third law of motion, which states that for every action, there is an equal and opposite reaction.
Newton’s laws apply to every movement we see around us, from jumping to driving! You can see Newton’s third law of motion in action when you are rowing in a boat. You use your paddle to move the water backwards, and as a result, your boat moves forward.
Science is everywhere! Take a look at our website for more fun experiments and demos.