Video says nothing about forces, however.
With this explanation it seems that if one wheel gets slightly stuck, the other wheel gets all the force, causing a dangerous spinning.
With this explanation it seems that if one wheel gets slightly stuck, the other wheel gets all the force, causing a dangerous spinning.
This is how a (open) differential behaves, though a spinning wheel isn't so much dangerous as ineffective. This limitation can be overcome using a locking differential or a limited-slip differential, or a traction-control system that selectively applies brakes to a spinning wheel to simulate a limited-slip differential.
So, while such simple differentials can get stuck fairly easily, they also work surprisingly well. The obvious trick is to apply some breaking power to the spinning wheel to then apply force to the stuck one, thus traction control. Or to just lock a differential when bouldering etc. More complicated mechanical systems can always provide some power to both wheels, but they aren’t actually necessary.
Your comment really shows how great the video is... That is exactly how an unlocked non-limited slip differential works, much to the irritation of anyone who has found themselves stuck in sand or a patch of ice.
Hence, if one wheel is stuck, it still receives the same force as the other, only speed is lower.
What is more annoying is when one wheel is freely slipping (like on ice), the other will have nearly no force applied to it and the car is stuck.
This is not necessarily true. Imagine a similar symmetric lever with a weight on one side, and a force on the axis that accelerates rotation. The acceleration of both ends of the lever are equal, but the force is not equal (since the weight is 0 on the other end).
Anyway, the point of my comment was that a thorough analysis of this configuration is more involved than this video of which it was claimed that it "perfectly" explains how this works.
Anyway, I did write "approximately" to avoid discussing acceleration/inertia of the differential itself. I should have written "in steady state" or something like that. It is true that a complete discussion can be more involved
i've learned about this the hard way about ten years ago: started my car, put it in first gear (manual), stepped outside and marveled at the freely spinning wheel on a patch of ice.
fortunately got a push from a stranger who happened to pass by.
Did you say youts?