A small sphere of radius r = 2cm and mass ‘m’ is placed on a big sphere of mass 2m and radius R = 10 cm, which is kept on a smooth horizontal surface as shown in figure. The displacement (in cm) of hemisphere when line joining between centre of small sphere and hemisphere make angle `30^(@)` with vertical is (Assuming that small spheres does not break-off the surface of hemisphere) -

Answer

2