A buoy is held inside water contained in a vessel by tying it with a thread to the base of the vessel. Name the three forces that keep the buoy in equilibrium and state the direction in which each force acts.

The three forces that keep the buoy in equilibrium are —

1. Weight of buoy acting in the vertically downward direction.
2. Upthrust of water on buoy acting in vertically upward direction.
3. Tension in thread acting in the vertically downward direction.