In mechanics, when we have an object in motion – say sliding along a table, we have dynamic friction. This is the friction of one object sliding along the other.
Both the mass of the object and the nature of the surfaces matter.
When the object is at rest though, before it starts sliding, we have static friction.
While dynamic friction can be tough, overcoming static friction is far more difficult.
The tricky thing is, if the object was sliding, but then comes to a rest, we are no longer dealing with dynamic friction.
We have to re-overcome static friction.
In the long game, continuation is hard. But stopping makes it even harder.
