A raft of wood (density`=600kg//m^(3))` of mass `120 kg` floats in water. How much weight can be put on the raft to make it just sink?

Options

A. 120 kg
B. 200 kg
C. 40 kg
D. 80 kg

Answer

D

Explanation

Volume of the raft`=(120kg)/(0.6xx10^3(kg)/(m^3))=200xx10^-3m^3`
When the raft just sinks,
Total weight of the raft (weight of the raft`+`weight put on the raft)`=`buoyancy of water
`=(200xx10^-3m^3)(1000(kg)/(m^3))=200kgwt`
Weight that can be put on the raft`=200kgwt-120kgwt=80kgwt`