|
Size: 1070
Comment:
|
Size: 2077
Comment:
|
| Deletions are marked like this. | Additions are marked like this. |
| Line 17: | Line 17: |
| ||A box of jumping discs||[:ThermoCabinetBayA3: TD, A3, Shelf #3]||<:>4A30.40 || | ||A box of Jumping Discs||[:ThermoCabinetBayA3: TD, A3, Shelf #3]||<:>4A30.40 || |
| Line 21: | Line 21: |
| 1. Make a Setup check list. 1. ... |
1. Hold the Jumping Disk in your palm. 1. 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. 1. Put the Jumping Disk on a cool, hard smooth surface such as the lecture table with the silver face down. 1. Stand back! Jumping Disk will jump into the air. |
| Line 25: | Line 27: |
| 1. List any Warnings.... 1. Demonstration may require practice. |
1. Do not put the Jumping Disk on a fine wooden furniture as it may scratch the surface. It is so powerful in its reaction. 1. If the Jumping Disk is not still in the clicked-in position, keep rubbing it until you put it down. |
| Line 31: | Line 33: |
| Insert description of demonstration, how is the demonstration preformed. | 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 cause the bimetallic disc to expand. then the 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 expand and contract at highly different rates due to the change in temperature. |
| Line 38: | Line 40: |
| 1. List any references | 1. EDMUND SCIENTIFIC CO. |
| Line 40: | Line 42: |
| [Insert a back link to main topic list] | [:ThermalProperties:Thermal Properties of Matter] |
Jumping Discs, 4A30.40
Location:
Cabinet: Thermodynamics Cabinet
Bay: (A3)
Shelf: #3
(attachment photo showing the fully set up demonstration)
Description:
Also called hopping discs, bimetallic jumpers.
Equipment |
Location |
ID Number |
|
|
|
A box of Jumping Discs |
[:ThermoCabinetBayA3: TD, A3, Shelf #3] |
4A30.40 |
Setup:
- Hold the Jumping Disk in your palm.
- 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.
- Put the Jumping Disk on a cool, hard smooth surface such as the lecture table with the silver face down.
- Stand back! Jumping Disk will jump into the air.
Cautions, Warnings, or Safety Concerns:
- Do not put the Jumping Disk on a fine wooden furniture as it may scratch the surface. It is so powerful in its reaction.
- If the Jumping Disk is not still in the clicked-in position, keep rubbing it until you put it down.
Demonstration:
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 cause the bimetallic disc to expand. then the 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 expand and contract at highly different rates due to the change in temperature.
attachment other photos |
attachment other photos |
attachment other photos |
attachment other photos |
References:
- EDMUND SCIENTIFIC CO.
[:ThermalProperties:Thermal Properties of Matter]
[:Demonstrations:Demonstrations]
[:Instructional:Home]