Question
An object experiences a net zero external unbalanced force. Is it possible for the object to be travelling with a non-zero velocity? If yes, state the conditions that must be placed on the magnitude and direction of the velocity. If no, provide a reason.
Solution
Yes, even when the net external force is zero, an object may travel with non-zero velocity.
A rain drop falls downwards with a constant velocity. The net force on the drop is zero because the weight of the drop is balanced by the upthrust and the viscosity of air.
