Particles of masses 1kg and 3kg are at (2i+5j+13k)m and (−6i+4j−2k)m then instantaneous position of their centre of mass is
14(−16i+17j+7k)m
14(−8i+17j+7k)m
14(−6i+17j+7k)m
14(−6i+17j+5k)m
r→cm=m1r→1+m2r→2m1+m2