When Does a Sliding Ladder Lose Contact With the Wall?

Rhett Allain
11 min readDec 22, 2023
Illustration: Rhett Allain. Python model showing a sliding ladder.

This started as a calculus problem. The question said that the top of a ladder moves down with some constant speed and asks about the speed of the contact point with the floor. You can see my solution here.

Of course my initial thought was not about derivatives of x and y, but instead I thought: I don’t think the top of a sliding ladder would move down with a constant…

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Rhett Allain

Physics faculty, science blogger of all things geek. Technical Consultant for CBS MacGyver and MythBusters. WIRED blogger.