- #1
Skrphys
- 9
- 3
I have my students doing a lab where they have to do and explain the tablecloth trick using Newton’s Laws. The problem I am having is that the one question asks why the quick removal of the tablecloth matters. I know friction is not affected by speed and yet this is the only force acting on the plate/cup in the direction of acceleration. So if speed doesn’t affect friction why can the trick not be done slowly? I have racked my brain thinking about it and I just can’t seem to come up with a good explanation. Any ideas on why this works this way? I know inertia makes the plate/cup “want” to stay at rest but that doesn’t explain why the friction doesn’t always cause the objects to fall.