Quick Answer: The Mechanical Paradox is the classic double cone on inclined rails: released at the lower-looking end, the cone seems to roll uphill. In fact its centre of gravity moves downward as it rolls.
Last updated: October 2026
Key Features
Double cone that rolls along a pair of inclined rails
Support frame and base for the rails
Cone appears to roll upward while its centre of gravity falls
Used for centre of gravity, stability, equilibrium and potential energy
About This Product
Students release the cone gently and watch it travel towards the higher end of the rails, then look closely at the height of its centre to see that it is actually dropping. The demonstration shows that motion follows the centre of mass rather than the outer surface and is a good prompt for scientific reasoning about apparent and real motion. The Mechanical paradox can be supplied on export terms to Chile, Syria, Botswana, São Tomé and Príncipe and Tajikistan.
Frequently Asked Questions
Why does the double cone seem to roll uphill?
Its centre of gravity is actually moving downward as it rolls along the rails, even though the cone appears to climb.
