# Magnetic Accelerator

(8 reviews)
• Magnetic Accelerator
Item #: MAG-400
• - +
• Magnetic Accelerator - 6 additional spheres
Item #: MAG-415
• 1 magnetic sphere, 5 non-magnetic.
• - +
Great for open-ended discovery!

Description

Place three seemingly identical spheres on a 3-foot horizontal track touching each other. Slowly roll another sphere slowly into the spheres at rest. Wow! All of a sudden one sphere takes off with tremendous velocity. Has the system gained energy? Could this be the basis of a perpetual motion machine? Hmm... Great for open-ended discovery! Colors may vary. Also available, six additional spheres for additional experimentation.

Read more on our Blog - The Magnetic Accelerator

Video

Lesson Ideas

Place three seemingly identical spheres on a horizontal track touching each other. Roll another sphere slowly into the spheres at rest. Wow! All of a sudden the last sphere takes off with tremendous velocity. The system seems to have gained energy!

Materials:
Track
Two wooden blocks
Five metal spheres (2.0 cm)
One magnetic metal sphere (2.0 cm)
(Safety glasses recommended, but not provided.)

Note: The track can be used in several different orientations: straight; raised 4.0 cm on either or both ends; and raised 6.0 cm on either or both ends.

Procedure A. Student Investigation

1. With the track raised 2.5 cm on each end, release one of the five metal spheres from one end of the track. What did you observe? At which point on the track does the sphere have the most Potential Energy? The most Kinetic?
(Expected observations: How high did it roll up the opposite side? How many changes in direction occurred before it stopped? How long was it in motion?)

2. Place two of the spheres at the bottom and release a third one from the end. What did you observe?

3. Experiment with different numbers of the five spheres at the bottom and releasing different numbers of spheres from the end of the curved track. What do you observe?

Teacher Note: As with Newton's cradle (NEW-100) both the kinetic energy and the momentum of the initial moving spheres are transferred to the final moving spheres. In this case, in order for both the Law of Conservation of Momentum (mv) and the Law of Conservation of Kinetic Energy (1/2 mv2) to hold, the initial moving spheres must equal the final moving spheres 'What comes in is what goes out.' Deviations are due to friction, and the slight magnetism of the spheres, causing them to stick together slightly and not roll well.

4. With two of the five spheres at the bottom of the curved track, release the special sphere given to you by your instructor. What did you observe?

5. With two of the five spheres and the one special one at the bottom of the curved track, release another sphere into the special one. What did you observe?

Teacher Note: As the released sphere gets closer to the stationary magnetic sphere at the bottom of the track, it becomes more and more attracted to the magnetic sphere. This causes a great increase in velocity. As a result, the sphere on the other end shoots out quickly. Notice that the final moving sphere is initially separated by another sphere from magnetic sphere. Consequently, it is attracted less to the magnetic sphere.

6. With only one end of the track raised and the other end near the edge of the table, set up the magnetic accelerator so that the final moving sphere travels the furthest. You can mark on floor with masking tape the final point of contact. Caution: the strong magnetic sphere is ceramic and may crack if dropped onto a hard surface.

7. With the track horizontal, place two of the five spheres and the one special one at the center as shown. With a pencil, slowly push a sphere from the end toward the special sphere. Observe.

Procedure B. Teacher Demo
Repeat steps 1 thru 5 from Procedure A in front of the class. Before each step, ask students to predict the result.

Procedure C. Open Ended
Provide students with all of the materials listed at the top. Ask them to experiment with the materials, carefully recording what they do and the results.

How does this activity demonstrate the Law of Conservation of energy?

Reviews

8 reviews
Associate Prof. Emeritus
Oct 31, 2015
This magnetic accelerator is great, even for quantitative measurements. I took a 120 fps video of the colliding spheres, from which I was able to determine the amount of magnetic potential energy that was converted to kinetic energy. I taped the magnetic and one steel sphere to the track so they would not recoil on the collision. Highly recommended.
Rich

2   0

Oct 2, 2015
It's great, but the magnetic marble begins to chip after a while.
Brian Laird

1   0

very useful for conservation of energy and not!
Mar 25, 2015
Easy to set up and rugged (no strings to tangle) can clearly demonstrate conservation of energy and when that concept is beginning to sink in just roll the magnetic sphere and astound your students with what looks like a serious exception.
Michael Thuot

2   0

replacements
Feb 18, 2015
So glad to have replacement parts
Blair Cochran

1   0

Useful demonstration - not a toy
Mar 22, 2014
This device is an excellent demonstration of Newton's Laws of Motion provided you keep to the non-magnetic balls. Once you introduce the magnetic ball (1) into the system all the 'laws' seem to go out the window (literally depending on your location!). The magnetic ball introduces a different energy source into the system - it's still Newtonian but the magnetic attraction between the steel balls and the magnetic ball can be very confusing - it is a secondary source of potential energy that increases in strength with the number of steel balls in the system. This can be very difficult to explain to students w/o a familiarity with the basic laws of magnetism. The system with five steel balls and a single magnetic ball appears to violate the conservation of energy principle - until the magnetic attraction effect is brought into the equations. This is, unfortunately, a complex function that is beyond most elementary Newtonian expressions and can reduce the teacher to hand waving (not a good situation despite the spectacular results of the fifth ball being shot off the end of the apparatus). Unless you are ready to explain magnetism to your students I would steer clear of this device - despite its wonderful simplicity. On the other hand, if you want to keep to strictly Newtonian physics (w/o magnets) this is an excellent device - it functions as a pendulum and momentum transfer demonstration that works at a low enough speed to allow students to observe and record data that reinforces the Newtonian laws to a 'T.' Worth the cost - and then some. wb
Warren Buckles

3   0

magnetic accelerator
Mar 13, 2013
What a great tool for teaching so many concepts of physics, including energy, and conservation of energy
Don Stokes

0   0

Crowd Pleasing Demonstration
May 30, 2012
The students in Science Club love to watch this demonstration. I do have a parent or older student helper closely monitor this activity since the steel balls can get lost and to make sure they aren't launched towards breakable objects.
Cynthia House

0   0

Great product
May 29, 2012
Great item.
Aaron Geery

0   0

### NGSS

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 Magnetic Accelerator to plan and conduct an investigation to compare the effects of different strengths or different directions of pushes and pulls on the motion of an object. K-PS2-2 Students can use the Magnetic Accelerator in an investigation to analyze data to determine if a design solution works as intended to change the speed or direction of an object with a push or a pull. 3-PS2-2 Students can use the Magnetic Accelerator in an investigation to understand motion. Students can make observation and/or measurements of an object's motion to provide evidence that a pattern can be used to predict future motion. 4-PS3-4 Students can use the Magnetic Accelerator to design, test, and refine a device that converts energy from one form to another. MS-PS3-5 Students can use the Magnetic Accelerator to construct, use and present arguments or experiments to support the claim that when the motion energy of an object changes, energy is transferred to or from the object. HS-PS2-1 Students can use the Magnetic Accelerator in an investigation to analyze data to support the claim that Newton's Second Law of Motion describes the mathematical relationship among the net force on a macroscopic object, its mass, and its acceleration. HS-PS2-2 Students can use the Magnetic Accelerator in an investigation and use mathematical representations to support the claim that the total momentum of a system of objects is conserved when there is no net force on the system. HS-PS3-4 Students can use the Magnetic Accelerator design, build, and refine a device that works within given constraints to convert one form of energy into another form of energy.

Suggested Science Idea(s)

K-PS2-1
K-PS2-2
3-PS2-2
4-PS3-4
MS-PS3-5
HS-PS2-1
HS-PS2-2
HS-PS3-4

Students can use the Magnetic Accelerator in a number of investigations to demonstrate and teach Newton's Laws of Motion. This science tool creates a dramatic demonstration of energy transfer, and much more.

* 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.

Q & A