Logo Print Disc for Promotion
USD $0.15 - $1.68 /Piece
Min.Order:2000 Pieces
Wuhu Boton Automobile Parts Factory
Why does the disc jump?
How it works!
The jumping disc is made from a special piece of metal, called bimetal that moves when heated with your thumb. When it is warmed to about body temperature, you can “click it” into its loaded position and then carefully place it on a hard surface. When it cools down to room temperature, it suddenly snaps back into the old position, and simultaneously jumps high up in the air. It jumps several hundred times its own height.
The discs are in interesting example of differential expansion. The disc is a bimetal, having stainless steel on one side and invar on the other. Invar is a nickel-iron alloy containing 36% nickel. This alloy has a very low coefficient of linear expansion by comparison with the stainless steel.
Heat causes the bimetal disc to expand and cooling makes it contract. Since the two surfaces expand and contract at highly different rates in response to changes in temperature, it is possible to 'lock' the disc in the loaded position when it is hot; then, as the disc cools, the increasing tension will eventually cause it to jump into the air as it reverts to its original shape!
The jumping disc works on the same principle as a thermostat or a shunt-valve in your car. With such a thermostat or automatic valve, a special piece of metal, called bi-metal, moves when heat is applied or removed. Bi-metal is actually two pieces of thin metal fused together in the middle. When the temperature changes, the metals expand differently and bend into a curve in either direction.
For instance, when the temperature drops in your home the bi-metal in your thermostat cools down, moves a little, hits a contact and turns on a heater. This way the temperature stays the same. In a car, the metal disc made of bi-metal opens or closes the valve to the radiator, so the water stays about the same temperature to make the engine run well.
In the case of the jumping disc, the bi-metal stays in one position when at room temperature, and in another position when at body temperature. First you warm it to body temperature in your hand, and then you snap the disc between your fingers so it stays in this “new” position. Now you carefully, and quickly, slide it onto a hard surface, like a table. In a few seconds the disc cools off, suddenly snaps back into the regular position, and with a loud “click” flies high into the air!
Games for your reference :
1. SOLITAIRE: This game is simply a matter of launching the disc and seeing how many concecutive times you can catch it. You may compete with others, or just try to beat your own record. If this gets too easy, try catching it on the back of your hand...or shutting your eyes until it pops.
2. UP-UP-AND AWAY: The player who can get this disc to pop the highest wins. (Note: This is not always easy to determine, so there should be an unbiased umpire, if possible.)
3. HIT THE STRING: Tie a string across and about 3 feet above the launching pad. The idea is to use your judgement (and a little guesswork) to determine the exact spot to launch the disc so that it will hit the string. Compete with your friends. The best out of five wins a round.
4. ON TARGET: The player who can land his disc closest to the launching spot (or some other pre-determined spot) wins.
5. FIELD GOAL: Played much like ”Hit the String” except that the object is to go over the string (without touching it) to score.
6. BLINK-NOT: Each person has to be positioned level with the disc and one foot away from it. Each player has 3 chances for each turn. The object is not to blink when the disc pops. The other players are judges...and the majority determines whether a player blinked or not.
Material information :
Working information :
Package information :
Setup and Procedure:
1 Hold the Jumping Disc in your palm.
2 Rub the silver side with your thumb until you feel warm. Then press down on the silver side until it clicks and make sure that it stays in the clicked-in position.
3 Put the Jumping Disc on a cool, hard smooth surface such as the lecture table with the silver face down.
4 Stand back! The Jumping Disc will jump into the air.
Cautions, Warnings, or Safety Concerns:
Discussion:
The Jumping Disk is a bimetallic disc that consists of stainless steel on one side and invar(nickel-iron alloy)on the other. The coefficient of linear expansion of the invar is much lower than that of the stainless steel. When you rub the silver side (stainless steel), heat produced by friction causes the bimetallic disc to expand. When the disc is placed on the table, cooling makes it contract. The change from the warm and cool caused the bimetallic disc to change shape immediately and jump into the air because the two surfaces contract at highly different rates due to the change in difference in their respective coefficients of thermal expansion.
These little metal discs are bimetallic - they are made from two different metals - and this enables them to perform an amazing physics trick!
The disc is slightly curved, and if you heat the disc in your hands you can then 'pop' the disk so that it bends the other way. You then place it on a flat surface, and it starts to cool. As it cools, the disc will, sooner or later, revert to the initial configuration. When this happens, the disc jumps several feet in the air!
Make sure your hands are not too cold - one customer reported problems in getting the discs to work. However he then realised that he had just come in from helping his son make a snowman in the garden, and his hands were really cold. Once his hands warmed up, the discs worked again!
One customer suggested holding the discs against a mug of hot tea, which certainly warms them up very effectively!
These discs were originally supplied by Edmund Scientific in New Jersey some 15-20 years ago. When the man in charge of the operation sadly passed away, nobody knew how to produce the discs anymore. Now a new designer in China has started making them again.
Thanks for your reading ! Have a nice day !