A raft of wood of mass 120 kg floats in water. The weight that can be put on the raft to make it just sink, should be (d_ raft =600 ~kg / m ^3 )

Step-by-step solution

Volume of raft is given by V= m d = 120 600 =0.2 ~m ^3 If the raft is immersed fully in water. Then weight of water displaced is =V d_ water =0.2 10^3=200 ~kg Hence, the additional weight which is supported by raft =200 ~kg -120 ~kg =80 ~kg