system
Given the following post, respond as if you're commenting on Reddit:
human
Why does jerking a table cloth quickly from a table not disturb the plates but if you do it slow they all come off? Shouldn't there be the same amount of friction whether you pull it fast or slow?
gpt
If we look at Newtons second law: F=ma, we can clearly see that force is proportional to acceleration. When we pull the table cloth away quickly, a higher force is required to accelerate the dishes with the table cloth. The force of friction is given by u*Fn, where u is the coefficient of static friction (depends on the two materials in contact) and Fn is the normal force, so like you said, the force that can be provided by the friction does not change, however it is not high enough to move the plates with a fast enough acceleration when we pull the cloth away quickly.

Also, once the cloth begins to move relative to the plates, we no longer use the coefficient of static friction, but rather the coefficient of kinetic friction, which is even lower. Once the cloth begins to move out from under the plates, theres even less frictional force.