A farmer uses the tractor’s low draw bar to pull a heavy load. Hooking a load higher on a tractor can make the vehicle tip or even flip.
Try it with two matching containers. Fill one (the tractor) with a few stones. Fill the other (the load) with a lot. Connect the containers underneath with masking tape. Put your finger low on the back of the “tractor” to act as the wheels, and nudge it forward. With a low draw bar, a heavy load doesn’t tip it.
Move the tape from beneath the tractor to its top edge. Nudge it forward in the same place. Its front tips up!
Art by: Robert L. Prince