Grade 11Mechanics

A cube of wood supporting 200 gm mass just floats in water. When the mass is removed. The cube ruses by
2 cm. What is the size of the cube?

Radhika Batra

12 Years agoGrade 11

5 Answers

Kevin Nash

12 Years ago

Hello Student,

Please find the answer to your question

Let the edge of cube be ℓ. When mass is on the cube of wood

200 g + ℓ³ d wood g = ℓ³ d_waterg

⇒ ℓ³ d_wood = ℓ³ d_water – 200 … (i)

When the mass is removed

ℓ³ d_wood = (ℓ - 2 ) ℓ² d_water … (ii)

From (i) and (ii)

ℓ³ d_water- 200 = (ℓ- 2) ℓ² d_water

But d_water = 1

∴ ℓ³ - 200 = ℓ² (ℓ - 2)

⇒ ℓ = 10 cm

Thanks
Kevin Nash
askIITians Faculty

SHAIK AASIF AHAMED

12 Years ago

Hello student,

Let the edge of the cube be x and the cube rises 2 cm on removing the mass. Thus, the weight of the body must be equal to the thrust provided by 2 cm height of the cube of base areas x2.

i.e. 200 g = (2 x2) 1 g

or x = 10 cm

Thanks and regards

Shaik Aasif

askIITians faculty

Gopivallabh

8 Years ago

A CUBE OF wood floating in water supports 200g mass resting at centre of its toop face . when mass is removed, cube rises 2cm . find out volume of cube

Shreya

8 Years ago

Let the edge of the cube be l cmWe know that mass=density× volumeVolume=area of the cube×heightGiven the cube rises by 2cm hence ht=2cmSo L×L×2×1g=200gm(density of water=1gm)L×L=100So l=10cm

Rishi Sharma

6 Years ago

Dear Student,
Please find below the solution to your problem.

Let the edge of the cube be x
cube rises 2 cm on removing the mass.
Thus, weight of the body must be equal to the thrust
provided by 2 cm height of the cube of base areas x2.
i.e. 200 g = (2 x2) 1 g
or x = 10 cm
Thanks and Regards