# Atal Tinkering Labs ATL

## Reflection of Light – Disappearing Coin Trick and the Science behind it.

When there is no water in the cup, the light from the penny experiences very little refraction and we can see the light from the penny.   When there is water in the cup, the light from the penny experiences refraction (bending) and reflection (total internal reflection, TIR) such the light it is not able to reach the observer’s eyes. A small amount of refraction occurs as the light leaves the penny and travels through the bottom of the cup, then refraction occurs again as it enters the water. When refraction occurs at the side of the cup there is…

## CLEAN A PENNY WITH VINEGAR

Why did the pennies look dirty before I put them in the vinegar? Copper atoms can combine with oxygen atoms to make a molecule called copper oxide. The pennies looked dull and dirty because they were covered with copper oxide.   Why did the vinegar and salt clean the pennies? Copper oxide dissolves in table salt-and vinegar because of its weak acid.   Why did the unrinsed pennies turn blue-green? When the vinegar and salt dissolve the copper-oxide layer, which makes it easier for the copper atoms to join oxygen and chlorine from the salt to make a blue-green compound…

## Egg drop with toilet paper experiment

Fill water glass about 3/4 way full, place pie tin on top of water glass, place paper tube on top of pie tin and directly over the whole of the water glass. then hit the pie tin from the side very quickly.   Why does the egg fall right into the glass? This was answered by Sir Isaac Newton’s First Law of Motion, which states that an object at rest remains at rest and an object in motion stays in motion with the same velocity unless acted upon by an unbalanced force.   Because the egg is not moving at…

## The Shaken-Soda Cans experiment

Two identical soda cans released at the same time on an incline will roll down at the same rate. However, if one of the cans is shaken, it will lose the race. Experimental evidence is presented that points to the presence of bubbles as the cause of the greater energy transfer to the fluid in the case of the shaken can.   The moment of inertia of the two cans is different.   When you shake one can, the gas inside the liquid tries to escape. It creates a foam that cannot escape and covers most of the unused volume…

## How to swing a glass of water in a circle experiment

It seems as if the water in the glass is defying gravity, but is it really? No. Gravity – the force pulling down on everything – is still at work even when the glass and water are above your head. The water’s inertia wants to keep the water traveling in a straight path, but gravity is acting on the water, causing it to fall in a downward path that will eventually hit the earth.   However, while the water is falling, the glass is falling with it, catching the water. What keeps the glass and water moving in a nice…

## Ivory Soap Experiment

Ivory’s first slogan, “It Floats!”, was introduced in 1891.   Ivory bar soap is whipped with air in its production and floats in water. Other brands of soap do not have as much air in it and will not have the same result. We did not test any other brands in the microwave.   When Ivory soap is heated in a microwave it gets hot and causes the soap to get soft. The microwaves beaming in the oven excite the water and air molecules inside the soap cause them to move in opposite directions from each other and vaporize. The…

## Coin launcher Experiment

When you cool air it shrinks, extra air is pushed into the bottle.   Then the wet coin seals the top of the bottle as it freezes. So as the temperature increases the pressure builds up.   This means that when you heat up the air again with your hands, it pushes outwards harder and harder until the pressure on the bottom of the coin is large enough to break the ice around it. As the ice breaks the coin is pushed upwards and flies away from the bottle.

## Ping Pong Ball BLAST OFF! Experiment

When I released the cup, the ball and water all fall together at the same speed, which increases as they continue to fall due to the force of gravity. The cup hits the ground first, then the water slams into the bottom of the cup. As water molecules pile up they collide with each other and create a compression wave that travels upwards very fast, like instantly. The water has much, much more mass than the ping pong ball, so when the upward moving wave collides with the downward moving ball a tremendous amount of energy and momentum is transferred…

## Touch and See Squares Experiment

Liquid crystals represent a phase in between liquid and solid. The molecules in a liquid crystal can move independently, as in a liquid, but remain somewhat organized, as in a crystal (solid).   These liquid crystals respond to changes in temperature by changing color. As the temperature increases, their color changes from red to orange, yellow, green, blue   What’s going on? The liquid crystal sheet is temperature sensitive, and an detect where your hand warmed the sheet.   Blue is the warmest, then green, orange and red. Black is the room temperature.   Blue – (82o – 86oF) Green…

## A Magnet Linear Accelerator Experiment

When the Magnet Linear Accelerator shoots, it will happen too fast to see. The ball on the right will shoot away from the gun, and hit the target with considerable force. Our one foot long version is designed so the speed is not enough to hurt someone, and you can use your hand or foot as a target.   How does it work? When you release the first ball, it is attracted to the first magnet. It hits the magnet with a respectable amount of force, and a kinetic energy.   The kinetic energy of the ball is transferred to…

## Floating Rice with Friction Experiment

Start off with a one question SURPRISE QUIZ. Its yes no answer and self grading. You can do it.   Can I lift a bottle full of rice by putting a chop stick in the bottle of rice?   Well lets see.   Don’t underestimate the Power of Friction. This is something that happens everyday, but we don’t notice it.   What’s Going On? When the rice is inside the bottle, there are grains next to one another, but there is a little bit of space — an air pocket — in between each grain and its neighbor. Which allows…

## Dancing Ping Pong Ball experiment

Why does this happen? Glass has a natural frequency where it vibrates. When you rub your damp finger on the outside of the glass your finger sticks to the glass because of friction and then slips because of the water which forms a cushion that reduces friction. When this slip and stick happens in equal intervals it causes the glass to vibrate.   The vibration from the glass pushes the air molecules around the glass in equal intervals, causing compression waves to form and ultimately make the sound we hear. The ping pong ball dances because it gets pushed by…

## The Spinning Ball experiment

Place the jar over the ball so that the ball is inside the mouth of the canning jar. Then start spinning the glass around in a circular motion. Once the ball starts spinning inside the glass lift it from the table top. The ball is lifted from the table and will continue to spin inside the glass until it loses is speed.   As a ball velocity increases inside the glass, the centripetal force increases. That force is what’s keeping the ball stuck to the walls of the glass.   As the ball goes faster, the resulting friction begins to…

## Magnetic Money Science Experiment

This experiment involves magnets, be aware of the danger of children swallowing them. Adult supervision is required.   Try holding the magnet over the \$1 bill and see which part is pulls up.   The Federal Reserve prints money they use a iron oxide which is magnetized when another magnet is present.   Vending machines use scanning technology called Magnetic Ink Character Recognition (MICR). This technology is use to find the magnetic pattern on it and to determine its denomination. Counterfeit detectors use similar technology to detect fake bills.

## Cups and ball Centrifugal Force Experiment

Now the object of this experiment is to separate the two balls – put one ball in each glass, this would seem tough. But just place the glasses on a table and spin them! The balls will be separated. The spinning glasses will make the balls fly towards the extreme ends.   When you swing an object around on a string or rope, the object will pull outward on the string. This is called the centrifugal force and is caused by the inertia of the object, where it seeks to follow a straight-line path. It is also called an inertial…

## How much water is in a ORANGE? Experiment

All living things must have water to survive. The good ol water cycle recycles water all the time. Evaporation is the change of liquid-water to water vapor. Evaporation of water occurs everyday whether it is in a cup or lake. Evaporation is a major part of the water cycle.   After the orange slices where completely dry, which took about 24 hours. You can speed up the process by using a hair dryer or fan. I just left mine in the sun the natural way. I put them back on the weighing scale. Remember the orange weighed 61 oz (1,803…

## Mpemba Effect

This phenomenon of hot water freezing faster than cold water is known as the Mpemba effect.   I tried this 3 times with the same results.   Hot water seems to freeze faster than cold water, known as the Mpemba effect. The effect was named after the Tanzanian student who in 1963 noticed that hot ice cream mix freezes faster than a cold one. The effect was first observed by Aristotle in the 4th century BC, then later Francis Bacon and René Descartes.   Theories for the Mpemba effect have included faster evaporation of hot water, therefore reducing the volume…

## Absorption and dissolving with sugar cubes in water experiment

When I pour the water on to the plate you noticed that the bottom sugar cube absorbs the colored water and it slowly moves upwards to the top sugar cube. This is because adhesive forces between the water molecules and the sugar molecules, along with cohesion with- in the liquid, allowed the water to move up the sugar cube tower against gravity. This process is called capillary action.   The reason sugar dissolves in a cup of coffee? It’s because of the way water molecules interact with molecules in other substances. A water molecule has powerful magnetic properties, because of…

## Paper Chromatography Experiment

Chromatography is a technique that is used by scientists to separate mixtures. A mixture is placed on paper and a liquid is added. As the liquid travels through the paper, it acts as a solvent and dissolves everything in the mixture, so the mixture begins to travel with the liquid.   The various components of a mixture all have different properties, so they will travel at different speeds and separate. For example, if we do paper chromatography with black ink, we will observe a separation of the colors that make up the black color! What pigments (colors) do you think…

## Separating Books Experiment

Start off with two books the same size, interleave them together. About one inch (2.54cm) overlapping. Then you and a partner pull as hard as you can to separate the books. You can’t do it, because Friction is a DRAG!   All that is holding the two books together is friction. This is the same force that acts to stop you sliding a book across a table.   When you interleave the two books there is a small force pulling the two books together created by the spine of the book.a table.   This compressive force will create a frictional…