Advertisements
Advertisements
प्रश्न
A metal cube of edge 5 cm and density 9 g cm-3 is suspended by a thread so as to be completely immersed in a liquid of density 1.2 g cm-3. Find the tension in thread. (Take g = 10 m s-2)
उत्तर
Given, side of the cube = 5 cm
∴ volume of the cube = 5 × 5 × 5 = 125 cm3
Density of metal = 9.0 g cm-3
Density of liquid = 1.2 g cm-3
Mass of the cube = volume × density
= 125 × 9 = 1125 g
∴ weight of the cube = 1125 gf (downwards)
Upthrust on cube = weight of the liquid displaced
= volume of the cube × density of liquid × g
= 125 × 1.2 ×
= 150 gf (upwards)
Tension in thread = Net downward force
= Weight of cube - Upthrust on cube
= 1125 − 150
= 975 kgf
= 9.75 N ...[∵ g = 10 m s-2]
Hence, tension in thread = 9.75 N
APPEARS IN
संबंधित प्रश्न
A sphere of iron and another of wood, both of same radius are placed on the surface of water. State which of the two will sink? Give a reason for your answer.
Complete the following sentence.
Density in kg m-3 = ............ × density in g cm-3
Differentiate between density and relative density of a substance.
The density of iron is 7.8 x 103 kg m-3. What is its relative density?
The relative density of silver is 10.8. Find its density.
A body weighs 20 gf in air and 18.0 gf in water. Calculate the relative density of the material of the body.
A solid weighs 32 gf in air and 28.8 gf in water. Find: (i) The volume of solid, (ii) R.D. of solid and (iii) The weight of solid in a liquid of density 0.9 g cm-3.
An aluminium cube of side 5 cm and RD. 2.7 is suspended by a thread in alcohol of relative density 0.80. Find the tension in thread.
A piece of wax floats in brine. What fraction of its volume will be immersed?
R.D. of wax = 0.95, R.D. of brine = 1.1.
