Will a swimmer gain or lose buoyant force as she swims deeper in the water?

Question

Will a swimmer gain or lose buoyant force as she swims deeper in the water? Or will her buoyant force remain the same at greater depths? Defend you answer.

Answer 1

It will go down a bit--not too much.

Buoyant force = density * g * displaced volume

Water is pretty much incompressible.  It's density does not change much when you go deeper.  The density may vary a bit with temperature, but that isn't going to be much either.

What may change a bit is the displaced volume.  If the swimmer had air in his/her lungs, it will be compressed, and the displaced volume will go down.

So the answer is that the swimmer is a bit less buoyant because the volume of water displaced is going to go down because of the increase in pressure.

Answer 2

gain as there is greater pressure the deeper you go - think of all the water above as pushing down , then the more there is the greater the force.