Question

explain why a further decrease in the elongation of the string was not observed when the stone was fully immersed in water

Answer 1

when the stone was immersed in the water completely, it experienced an upthrust which goes on increasing until the object completely immerses. but in this case the stone was completely immersed in water so it did not experience any further upthrust due to which the elongation of the string did not decrease further

Answer 2

Answer:

There was a decrease in the elongation because when the object is fully immersed in the liquid it did not experience any upward force