Question

Give reasons for the following :

(a) A balloon collapses when air is removed from it.

(b) Water does not run out of a drpooer unless its rubber bulb is pressed.

(c) Two holes are made in a sealed oil tin to take out oil from it.

Answer 1

(a) Atmospheric pressure which is more than inside pressure of balloon causes the balloon to collapse.

(b) Atmospheric pressure acting from outside the dropper balances the pressure exerted by water and water does not come out of a dropper. On pressing the dropper inside pressure of water becomes more than outside atmospheric pressure and water runs out.

(c) Two holes are made in a sealed can so that atmospheric air presses the oil at one hole and oil comes out of the second hole.