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 textraft =600 kg / m 3)

Question

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 textraft =600 kg / m 3) (A) 80 kg (B) 50 kg (C) 60 kg (D) 30 kg

Tardigrade Admin · Accepted Answer

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 text water =0.2 × 103=200 kg Hence, the additional weight which is supported by raft =200 kg -120 kg =80 kg

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

80 kg

50 kg

60 kg

30 kg

Volume of raft is given by
$V = \frac{m}{d} = \frac{120}{600} = 0.2 m^{3}$
If the raft is immersed fully in water.
Then weight of water displaced is $= V d_{water}$
$= 0.2 \times 1 0^{3} = 200 k g$
Hence, the additional weight which is supported by raft
$= 200 k g - 120 k g = 80 k g$

Q. A raft of wood of mass 120kg floats in water. The weight that can be put on the raft to make it just sink, should be (draft​=600kg/m3)