Here's why:
* Buoyant force is the upward force exerted by a fluid (like water or air) on an object submerged in it.
* Weight is the downward force of gravity acting on an object.
When these two forces are equal:
* The upward buoyant force perfectly balances the downward force of gravity.
* The object is in equilibrium.
* The object will neither sink nor rise, it will remain suspended in the fluid.
This is the principle behind why ships float, hot air balloons rise, and why some objects sink while others float.
