Question

If the density of my body is less than that of water I should float on water, but as I go deeper in water , the water above exerts pressure on me, thereby it may increase my weight, then will I sink or again come back on the surface ?

Answer 1

Very good question.

If no other constraints are there, you would come back to the top of water, no matter how deep you go, even though you should not try this for real.




You know that pressure acts in all directions, and also pressure increases with depth.


When an object is inside water the pressure acting along the sides almost cancel each other as they are equal.

But the water below the object(at more depth) exerts more pressure than the water above the object(less depth).Thus there will be a net upward force called Buoyant force.


So,
When an object is immersed in a fluid, the upward force on the bottom of an object is greater than the downward force on the top of the object. The result is a net upward force (a buoyant force) on any object in any fluid. If the buoyant force is greater than the object’s weight, the object will rise to the surface and float. If the buoyant force is less than the object’s weight, the object will sink. If the buoyant force equals the object’s weight, the object will remain suspended at that depth. The buoyant force is always present in a fluid, whether an object floats, sinks or remains suspended.