A guide to science fair development

Transcription

1 LINX Science Camps A guide to science fair development

2 Toilet Paper Party Physics, Electricity, Flight Supplies: Hair Dryer (x1) Leaf Blower (x6) Toilet Paper Rolls (x30) Extension Cord (20 ) Power strip (6 outlets) Paint Rollers (2 mini, 6 jumbo) Tarp to cover project (10 x 20 ) Tape measure (30 ) How many squares are in a roll of toilet paper How many squares are in 20 rolls of toilet paper How far can you throw a roll of toilet paper Can you throw the toilet paper in different ways to get it to unroll faster Have each group discuss and brainstorm ways they can unroll a roll of TP the fastest Give each group a roll of TP and see who can unroll the TP the fastest What are ways we can get to unroll the toilet paper faster in the future Get ready to make a mess, with toilet paper! Ever wonder how many sheets of toilet paper are in a roll of toilet paper? Ever wonder how fast you could unroll toilet paper off it s roll? Wonder if there is science in unrolling a roll of toilet paper? Get ready to see the fastest way to unroll toilet paper using physics, Electricity, Principles of Flight! The flying toilet paper is a wonderful example of Bernoulli's Principle, the same principle that allows heavier than air objects like airplanes to fly. Bernoulli, an 18th century Swiss mathematician, discovered something quite unusual about moving air. He found that the faster air flows over the surface of something, the less the air pushes on that surface (and so the lower its pressure). The fast moving air from the leaf blower flies above the toilet paper roll causing an area of low pressure. The slower moving air under the roll causes an area of higher pressure. The difference in pressure between the fast moving air above the roll and the slower air underneath it creates lift. This lift causes the toilet paper to fly off of the roll. Airplanes can fly because of Bernoulli's Principle. Air rushing over the top of airplane wings exerts less pressure than air from under the wings. So the relatively greater air pressure beneath the wings supplies the upward force, or lift, that enables airplanes to fly. That s why airplanes have to drive down the runway and gain speed before they lift off. The jet engines keep the airplane moving through the air continuously creating lift.

3 Elephant Toothpaste Supplies: Chemistry, Biology, Exothermic Chemical Reaction Erlenmeyer flask 1/2 cup 20 volume hydrogen peroxide liquid (20 volume is a 6% solution, ask an adult to get this from a beauty supply store or hair salon) 1 Tablespoon (one packet) of dry yeast 3 Tablespoons of warm water Liquid dish washing soap Food coloring beaker Safety goggles 6 tubes of crest toothpaste 12 $1 toothbrushes 12 bottles of water 2 rolls of paper toweling How many teeth do you think an elephant has? How big the average tooth in an elephant s mouth? How much toothpaste do people use when they load up their toothbrush? How much toothpaste would an elephant use to brush its teeth just once? Group Challenges: Call up a volunteer from each group and blindfold him/her Each person has in front of them a toothbrush/bottle of water and toothpaste On the GO command, they have to load their, brush, brush for 30 seconds and rinse! Would bubble solution change the reaction? Would laundry detergent? Hold onto your seats kids because we need to make enough toothpaste for an Elephant to be able to brush his teeth! All it will take is a few ingredients and a little chemistry, and watch and see what happens right before your eyes! More things you can do to test this out! 1. Does the amount of yeast change the amount of foam produced? 2. Does the experiment work as well if you add the dry yeast without mixing it with water? 3. Does the size of the bottle affect the amount of foam produced? This experiment created a reaction called an Exothermic Reaction. Exothermic Reactions create a lot of heat! You might have felt something like this with a hand warmer in the Winter. The foam produced is just water, soap, and oxygen. DO NOT PUT THE FOAM IN YOUR MOUTH! Each tiny foam bubble is filled with oxygen. The yeast acted as a catalyst (a helper) to remove the oxygen from the hydrogen peroxide. Since it did this very fast, it created lots of bubbles. The opposite of an Exothermic reaction is an Endothermic reaction that takes away heat or makes things colder. If you get hurt, then you might get an instant ice pack. When the chemicals mix in the ice pack, it creates an endothermic reaction and gets cold. It will keep getting colder as the chemical reaction continues.

4 Let It Fly Bernoulli s Principle, Electricity, Flight Electricity and Flight, Bernoulli s Principle, Pressure, Gravity Supplies: Ping Pong Balls (6) Hairdryer Leaf Blower Extension Cord (30 ) Beach ball straws (30) LINX Hovercraft How can we make an object float on air How far off a surface can we make a ping pong ball float (inches) How long can you make it float? Could you float a tennis ball? How about a beach ball? Have each group send up two volunteers One member of a team gets a straw, the other places the ping pong ball on the straw On the GO command the team that suspends their ball over their straw the longest wins! With the help of Bernoulli s Principle we will see objects, big and small hover and float! How big an object can we lift? This is an example of Bernoulli s principle fast moving air creates low pressure and slow moving air creates high pressure, all causing lift. The floating ping pong ball and beach ball is also about the epic battle between gravity and lift. Gravity wants to pull everything down to Earth rocks, people, animals, everything gets pulled down by gravity. Bernoulli s principle helps create lift which can fight back against gravity. The air from the hair dryer flows around the outside of the ball and, if you position the ball carefully, the air flows evenly around each side. Gravity pulls the ball downwards while the pressure below the ball from the moving air forces it upwards. This means that all the forces acting on the ball are balanced and the ball hovers in mid air. As you move the hair dryer you can make the ball follow the stream of air because Bernoulli's Principle says that the fast moving air around the sides of the ball is at a lower pressure than the surrounding stationary air. If the ball tries to leave the stream of air, the still, higher pressure air will push it back in. So, the ball will float in the flow no matter how you move.

5 Air Pressure Rockets Supplies: Chemical Reactions, Flight Alka seltzer test tubes with caps Corked test tubes shaving cream two liter blaster aqua pod with shaving cream bike pump food coloring/water soap How far do you think the caps can go? How much air pressure do you think is building inside How long do you think the Alka seltzer tablets will last Do you think the size of the container will affect the time of the pop would more Alka seltzer make a bigger pop? Have each group send up 3 volunteers On holds the tube, one puts the tablet in, one caps bucket of caps to replace Have them only point it into the air How do rockets work? We are going use air pressure to create thrust blasting our mini rockets into the air! Watch as we blast this cork into the air. We will start with the little test tubes and then use the flask and cork! This will shoot to the ceiling and send a plum of soapy water in a 15 foot circumference. This will simulate a rocket blasting This exciting experiment is all about chemical reactions and pressure. When you mix alka seltzer into water, a chemical reaction occurs. This mixture creates carbon dioxide (CO 2 ) gas, the same gas that you breath out. This gas needs to go somewhere, and it doesn t like to be contained. When it is contained, pressure builds and builds until BOOM the rocket flies! The lid of the canister is the path of least resistance for the gas pressure building up inside, so it pops off instead of the stronger sides or bottom of the canister bursting open. The ideas of Sir Isaac Newton come in next. When the buildup of carbon dioxide gas is too great and the lid pops off, Newton's Third Law explains why the film canister flies across the room: for every action there is an equal and opposite reaction. The lid goes one way and the rocket shoots in the opposite direction. The rocket will keep flying until our old friend gravity brings it back to Earth.