The opening near the bottom of the vessel shown has an area A. A disk is held against the opening to keep the liquid, from running out. It is given that net force on the disk applied by liquid and air in this case is F. Now the disc is moved away from the opening by a short distance. The liuid comes out and strikes the disk inelastically. What will be the initial force exerted by the liquid on the disk in this condition.

Answer

2

Explanation

`F_(1)=rhoghA," "F_(2)=` rate of change in momentum `=rhoAv^(2)=rhoA(sqrt(2gh))^(2)=2rhoghARightarrow(F_2)/(F_1)=2`