After impact the string rotates through an angle 120 degrees ,find the velocity when the block ceases to perform circular motion. Share with your friends Share 3 Shobhit Mittal answered this Dear student, velocity of bullet at highest point is =ucosθby momentum conservationmucosθ=mucosθ2+Mvv=mucosθ2M intial velocity of block.by energy conservation we can find the velocity at point where circular motion ceases.Mv22=Mgl+lsin30+Mv'22v22=gl+lsin30+v'22v22-gl+lsin30=v'22v2-2gl+lsin30=v'2v'=mucosθ2M2-3gl this is the velocity of block at 120 degreeRegards 1 View Full Answer