Question

Which object is in static equilibrium?

a rolling ball that has a net force acting on it
a cruising car that has no net force acting on it
a book that has no net force acting on it and is sitting on a table
a vase that has a net force acting on it and is sitting on a shelf

Answer 1

In order for an object to be in static equilibrium the net external forces acting on the object has to equal zero and should be in rest state.