Bimetallic Jumping Disk

A curved jumping disk? The sky's the limit for these disks, which have two layers of bonded metals with different thermal expansion properties. A change in temperature causes these disks to jump approximately 12 inches or higher into the air! Simple enough for elementary students; challenging enough for AP physics classes! 25 mm (1") dia. Pkg. of 10.

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Very Disappointing

Feb 20, 2018 | By John H. Bordelon of Marietta, GA United States

I had one of these 50 years ago that I picked up at a convention. Worked great so I bought several of the ones here to give to the grandchildren. The original one I had would jump about 18 inches. These won't make it more than an inch or so off the table. They are much too thick to work properly.

Technician

Feb 18, 2014 | By Ed Dudak of Grinnell, IA United States

Disc has to be heated a lot to get into 'jumping' position. It takes more than just holding in your hand. I used a heat gun to get it to flip then it flipped back pretty quickly. There was a time long ago when you could get these kind of discs that would respond to just warm hands. I guess they just don't make them anymore. Too bad.

fun

Feb 1, 2014 | By Stephanie of Wichita Falls, TX United States

Sometimes hard to warm up

Energy

Oct 4, 2013 | By Marco of West Covina, CA United States

These are a great item to use for the implementation of New Generation Science Standard. A tremendous part of physical science standards now has Energy. These items provide a great lab experiment for the energy standards. The following standard would apply: MS-PS3-3. Apply scientific principles to design, construct, and test a device that either minimizes or maximizes thermal energy transfer. Plus these items are the cheapest on any website I have seen!

Jumping disks?

Sep 30, 2013 | By Doug Spicher of MD United States

These disks do jump, but nearly as high as claimed and only after the user inverts them. Might be confusing to kids as to whether it is energy or it is the expansion of the metal.

Owner Response:This is true; the user must invert the disk to initially store the energy, but it is not possible to invert the disk until you warm the disk. The disk will remain inverted until it cools to a temperature where one metal contracts more than the other causing the disk to release its energy. These disks are used to demonstrate the different conduction rates between the two different metals.

Wow!

Jan 25, 2013 | By Geoff of Brooklyn, NY United States

I've been looking for these for years! It seems they were off the market and finally returned. I purchased several bags and think they are a bargain! What a great way to teach expansion of metals!

Pricey

Jan 20, 2013 | By Martin of St-Georges, QC Canada

Works but pricey, better buy a bi-metal compound bar that is much bigger and you can see the change while the bar is beeing heated

teacher

Dec 27, 2012 | By Warren of New York, NY United States

good

This product will support your students' understanding of the Next Generation Science Standards (NGSS)*, as shown in the table below.

Elementary

Middle School

High School

K-PS2-1

Students can use the Bimetallic Jumping Disk to plan and conduct an investigation to compare the effects of pushes and pulls on the motion of an object.

2-PS1-4

Students can use the Bimetallic Jumping Disk in an investigation to construct an argument with evidence that some changes caused by heating or cooling can be reversed and some cannot.

3-PS2-2

Students can use the Bimetallic Jumping Disk to make observations and/or measurements of an object's motion to provide evidence that a pattern can be used to predict future motion.

4-PS3-2

Students can make observations of the Bimetallic Jumping Disk to provide evidence that energy can be transferred from place to place by heat.

4-PS3-4

Students can use the Bimetallic Jumping Disk in an investigation to apply scientific ideas to design, test, and refine a device that converts energy from one form to another.

5-PS1-3

Students can use the Bimetallic Jumping Disk to make observations and measurements to identify materials based on their properties.

MS-PS1-4

Students can use the Bimetallic Jumping Disk in an investigation to develop a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed.

MS-PS3-2

Students can use the Bimetallic Jumping Disk in an investigation to develop a model to describe that when the arrangement of objects interacting, different amounts of potential energy are stored in the system.

MS-PS3-4

Students can use the Bimetallic Jumping Disk in an investigation to determine the relationships among the energy transferred the type of matter, the mass, and the change in the average kinetic energy of the particles as measured by the temperature of the sample.

DCI-MS/PS3A: Definitions of Energy.

A system of objects may also contain stored (potential) energy, depending on their relative positions.

HS-PS2-6

Students can use the Bimetallic Jumping Disk in an investigation to observe and communicate scientific information about why the molecular-level structure is important in the functioning of a material.

HS-PS2-6

Students can use the Bimetallic Jumping Disk in the design of a device that works with given constraints to convert one form of energy into another form of energy.

Suggested Science Idea(s)

K-PS2-1
2-PS1-4
3-PS2-2
4-PS3-2
4-PS3-4
5-PS1-3
MS-PS1-4
MS-PS3-2
MS-PS3-4
DCI-MS/PS3A
HS-PS2-6
HS-PS2-6

Simple enough for elementary students; challenging enough for AP physics classes! Students can investigate both the structure of the disk and potential energy it possesses. These disks, which have two layers of bonded metals with different thermal expansion properties, will release the potential energy to kinetic energy when a change in temperature occurs. It causes these disks to jump approximately 12 inches or higher into the air!

The bi-metal stays in one position when at room temperature, and in another position when at approximately 98 degrees F. For a simple investigation, warm the Bimetallic Jumping Disk to about 98 degrees in your warm hand, and then snap or click the disk between your fingers. Place it on a table or flat surface. When the metal is warmed enough, the disk will remain in the 'inverted' position (potential energy) until it cools down. When the disk cools, it will jump up and be restored to the original position.

* NGSS is a registered trademark of Achieve. Neither Achieve nor the lead states and partners that developed the Next Generation Science Standards were involved in the production of, and do not endorse, this product.