A nucleus disintegrates into two nuclear parts which have their velocities in ratio 2 : 1. The ratio of their nuclear sizes will be

According to law of conservation of momentum, we getm1v1=m2v2 or m1/m2=v2/v1 But m=43πr3ρ  or  m∝r3 ∴ m1m2=r13r23  Therefore, r13r23=V2V1=12 or r1r2=121/3 r1:r2=1:(2)1/3