On Feb 9, 4:39 pm, (Doug Miller) wrote:

...

Again, incorrect. Changing the size or shape of the contact area does not
change the amount of friction.


This is true. Yet if you want to slide a heavy object,
it helps to put it on skids, even if the object has a
flat side and it's on a hard surface. I've never been
able to figure out why.

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FF