Advertisements
Advertisements
Question
Why does a helium balloon float in air?
Advertisements
Solution
Helium is much less denser than ordinary air which gives them buoyancy and thus float in air.
APPEARS IN
RELATED QUESTIONS
A body is held immersed in a liquid. (i) Name the two forces acting on the body and draw a diagram to show these forces. (ii) State how the magnitudes of two forces mentioned in part (i) determine whether the body will float or sink in liquid when it is released. (iii) What is the net force on the body if it (a) sinks and (b) floats?
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?
For a floating body, its weight W and upthrust FB on it are related as :
A body of weight W is floating in a liquid. Its apparent weight will be
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 rubber ball floats in water with 2/7 of its volume above the surface of the water. Calculate the average relative density of the rubber ball.
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.
Explain the following:
An egg sinks in fresh water but floats in a strong solution of salt.
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.
How do submarines sink and float in water?
