Advertisements
Advertisements
प्रश्न
A block of wood of volume 25 cm3 floats in water with 20 cm3 of its volume immersed in water.
Calculate:
(1) density of wood
(2) the weight of block of wood.
उत्तर
Volume of wooden block = V = 25 cm3
Volume of wooden block immersed in water = 20 cm3
Volume of water displaced by wooden block=volume of wooden
block immersed in water = 20 cm3
Density of water = ρwater = 1 gcm-3
Density of wooden block =ρwood = ?
By law of floatation:
volume of wooden block x Density of wood=Volume of water displaced x Density of water
`25 xx rho_"wood" = 20 xx 1`
`rho_"wood" = 20/25 = 0.8` g cm-3
Weight of wooden block `"V"rho_"wood""g"`
= 25 × 0.8 × g = 20 gf
APPEARS IN
संबंधित प्रश्न
A hollow metal cylinder of length 10 cm floats in alcohol of density 0.80 g cm-3, with 1 cm of its length above it. What length of cylinder will be above copper sulphate solution of density 1.25 g cm-3?
What fraction of metal of density 3400 kgm-3 will be above the surface of mercury of density 13600 kgm-3, while floating in mercury?
A test tube weighing 17 gf, floats in alcohol to the level P. When the test tube is made to float in water to the level P, 3 gf of the lead shots are added in it. find the R.D. of alcohol.
A test tube loaded with lead shots weighs 25 gf and floats upto the mark X in water. When the test tube is made to float in brine solution, it needs 5 gf more of lead shots to float upto level X. Find the relative density of brine solution.
A cube of ice whose side is 4.0 cm is allowed to melt. The volume of water formed is found to be 58.24 cm3. Find the density of ice.
State the principle of floatation. What can you say about the average density of a ship floating on water?
Why does a helium balloon float in air?
Assertion: To float, body must displace liquid whose weight is equal to the actual weight.
Reason: The body will experience no net downward force in that case.
Assertion (A): Lactometer is used to check the purity of milk.
Reason (R): Lactometer measures the cream content of milk.
