since 5 kg body explodes into three fragments with masses in the ratio 1: 1: 3 thus, masses of fragments will be 1kg,1kg and 3 kg respectively. The magnitude of resultant momentum of two fragments each of mass 1kg, moving with velocity 21m∕s, in perpendicular directions is √(m1v1)2+(m2v2)2 m′v′=√(21)2+(21)2=21√2kgm∕s According to law of conservation of linear momentumm3v3=m′v′=21√2 or 3v3=21√2 or v3=7√2m∕s