Question

A wooden cube of side $10$ cm is floating in water kept in a cylindrical beaker if base area $1500$ cm When a mass m is kept on the wooden block the level of water rises in the beaker by $2$mm Find the mass m.

• A. 200g
• B. 300g
• C. 400g
• D. 500g

Answer 1

Answer: (B)

300g

If water level rises by $2mm$ or $0.2cm$ in the cylindrical beaker of base area 1500 ${cm}^2$ due to keeping of mass m on the floating cube then volume of water more displaced for this will be $V=1500\times 0.2=300{cm}^3.$

The mass of this water will represent the mass of m. Since the weight of the mass is the weight of the displaced water following the condition of floatation.

So mass of m =mass of 300${cm}^3$ water=$300\times 1g=300g$ (Considering density of water as 1 g${cm}^{-3}$)

$Som=300g$