question_answer 45)

                  A vessel filled with water is kept on a weighing pan and the scale adjusted to zero. A block of mass M and density \[\rho \]is suspended by a massless spring of spring constant K. This block is submerged inside into the water in the vessel. What is the reading of the scale?                

Answer:

                  The new reading of the scale will be equal to the upthrust \[=\rho \,Vg,\] where, \[\rho \] is density of water.