Museum of Science and Industry

Make a Comeback Can

Step 7 of 7: What's happening?

Key Terms Defined

Kinetic energy
Energy from motion
Potential energy
Stored energy that transforms into kinetic energy.

To understand how the comeback can works, you have to understand energy. Energy comes in many forms. One form of energy is motion, called kinetic energy. Another form is stored, or potential energy. The comeback can uses both forms.

When you push the can, you give it kinetic energy and it moves away from you. The hex nut holds one length of rubber band still while the rolling can causes the other rubber band to twist around it. The can rolls until the rubber band is completely twisted. This is when kinetic energy becomes potential energy - the can is not moving, but it has the ability to do so. As the rubber band unwinds, the potential energy again becomes kinetic energy and the can rolls back to you.

Museum Hours
  • Daily from 9:30 a.m. to 4 p.m.
    Open daily except Thanksgiving and Christmas
More Information

Museum Location
Museum of Science+Industry
5700 S. Lake Shore Drive
Chicago, IL 60637
1 (773) 684-1414
Getting Here

Buy Tickets Online

More Activities

All Online Activities

More Exhibits

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    Feel the physics and consider the chemistry of natural phenomena like tornados and avalanches.


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