Wheel versus sled: why a cart is easier
A sled and a cart get the same push. The sled quickly stops while the wheeled cart rolls much farther.
2D
Age 6+10 min
RollingFrictionMachines & mechanisms
Loading simulation…
Press “Run”. Bodies move by the laws of physics: gravity, friction, elasticity.
What the experiment shows
A sled slides on the ground and sliding friction quickly takes its speed. A wheel doesn’t slide, it rolls — only the axle friction slows it.
How to run it
- Press “Run” and compare which went farther.
- Make the wheels square (replace them with rectangles).
- Put a load on the cart.
Questions to discuss
- Why is the wheel called one of the greatest inventions?
- Where else is rolling used instead of sliding?
The science
Rolling resistance is tens of times smaller than sliding friction: the wheel’s contact point doesn’t slip. That is why bearings and rollers make loads much easier to move.
Try it at home
Drag a book across a table, then put it on pencils as rollers. Feel the difference.
What to change in the editor
- Double the push.
- Make the wheels small.