A raft of wood(density=600 kg/m^3) of mass 120 kg floats in water.how much weight can be put on the raft to make it just sink
we know that
weight of water displaced = weight of raft + mass
so,
ρwVg = Mg
here, M = mass of raft + mass = (120+m) kg
thus,
ρw=1000 kg m-3
ρwVg = (120+m).g
m + 120 = ρwV = 1000 x V
so,
m + 120 = 1000 x V
V(volume of water displaced=Volume of raft)=120/600=.2 m3
m=.2x1000-120
m=80 kg