Advertisements
Advertisements
प्रश्न
Why does a helium balloon float in air?
Advertisements
उत्तर
Helium is much less denser than ordinary air which gives them buoyancy and thus float in air.
APPEARS IN
संबंधित प्रश्न
When a piece of wood is suspended from the hook of a spring balance, it reads 70 gf. The wood is now lowered into water. What reading do you expect on the scale of spring balance?
A solid iron ball of mass 500 g is dropped in mercury contained in a beaker. (a) Will the ball float or sink? Give reasons. (b) What will be the apparent weight of the ball?
A body of volume V and density ρs , floats with volume v inside a liquid of density ρL. Show that `"v"/V = ρ_s/ρ_L` .
Why is the floating ice less submerged in brine than in water?
A test tube loaded with lead shots, weighs 150 gf and floats upto the mark X in water. The test tube is then made to float in alcohol. It is found that 27 gf of lead shots have to be removed, so as to float it to level X. Find R.D. of alcohol.
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.
State the principle of floatation. What can you say about the average density of a ship floating on water?
Explain the following:
Icebergs floating in the sea are very dangerous for ships.
Why do petroleum-based products float on the surface of the water?
