Take a piece of stone and tie it to one end of a rubber string or a spring balance. Suspend the 'stone by holding the balance or the string as shown in the figure. Note the elongation of the string or the reading on the spring balance due to the weight of the stone. Now, slowly dip the stone in the water in a container as shown. Observed what happens to elongation of the string or the reading on the balance. , -

Explanation

We will find that elongation of the string or the reading of the balance decreases as the stone is gradually of the balance decreases as the stone is gradually lowered in water. However, no further change is observed once the stone gets fully immersed in the water.