The correct option is D 1.2√5(2−√3)
After impact, rod rebounds 30o from vertical.
By conservation of energy,
mgl2(1−cos300)=12ml23w22
⇒mgl2(1−√32)=12ml23ω22
⇒ω2=
⎷3(1−√32)gl
Velocity of point R after impact
v2=ω2x = ⎡⎢
⎢
⎢
⎢
⎢
⎢⎣3(1−√32)X10l⎤⎥
⎥
⎥
⎥
⎥
⎥⎦×0.6 (since x=0.6m)
⇒v2=1.2√5(2−√3)m/s