Advertisements
Advertisements
प्रश्न
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.
Advertisements
उत्तर
Side of an aluminium cube = l = 5 cm
Volume of aluminium cube = V = Z3 = (5)3 =125 cm3
Relative density of aluminium = R.D. = 2.7
Relative density of alcohol = R.D. = 0.80
Density of water = 1 g cm-3
R.D. of aluminium = `"Density of aluminium"/"Density of water"`
`2.7 = "Density of aluminium"/1`
Density of aluminium =ρ = 2.7 g cm-3
Mass of aluminium = V x ρ
m = 125 x 2.7 = 337.5 g
Wt. of aluminium cube acting downwards = 337.5 gf
Volume of alcohol displaced = Volume of cube = V = 125 cm3
Upthrust due to alcohol = `"V"xxrho_"alcohol" xx "g"`
Now R.D. of alcohol = `rho_"alcohol"/"Density of water"`
`0.80 = rho_"alcohol"/1`
`rho_"alcohol" = 0.80` g cm-3
⇒ Upthrust due to alcohol = `"V" xx rho_"alcohol" xx "g"`
= 125 × 0.80 × g = 100 gf
So tension in threat = Wt. of aluminium cube - Upthrust
= 337.5 - 100 = 237.5 gf
APPEARS IN
संबंधित प्रश्न
A solid of density 5000 kg m-3 weighs 0.5 kgf in air. It is completely immersed in water of density 1000 kg m-3. Calculate the apparent weight of the solid in water.
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)
The relative density of mercury is 13.6. State its density in
(i) C.G.S. unit and
(ii) S.I. unit.
A piece of stone of mass 15.1 g is first immersed in a liquid and it weighs 10.9 gf. Then on immersing the piece of stone in water, it weighs 9.7 gf. Calculate:
- The weight of the piece of stone in air,
- The volume of the piece of stone,
- The relative density of stone,
- The relative density of the liquid.
A glass cylinder of length 12 x 10-2 m and area of crosssection 5 x 10-4 m2 has a density of 2500 kgm-3. It is immersed in a liquid of density 1500 kgm-3, such that 3/8. of its length is above the liquid. Find the apparent weight of glass cylinder in newtons.
A solid weighs 0.08 kgf in air and 0.065 kgf in water. Find
(1) R.D. of solid
(2) Density of solid in SI system. [Density of water = 1000 kgm3]
A solid of R.D. = 2.5 is found to weigh 0.120 kgf in water. Find the wt. of solid in air.
An iceberg floats in sea water of density 1.17 g cm 3, such that 2/9 of its volume is above sea water. Find the density of iceberg.
