When a golf ball is lowered into a measuring cylinder containing water

cbse
floatation

#1

(i) When a golf ball is lowered into a measuring cylinder containing water, the water level rises by 40 ${{cm}^{3}}$when the ball is completely submerged. If the mass of ball in air is 44 g, calculate its density.
(ii) A 1/2 kg sheet of tin sinks in water but, if the same sheet is converted into a boat or a box, it floats. Give reason.


#2

(i)Given, mass of ball,m = 44 g
Volume, V = 40 ${{cm}^{3}}$
Density = m/V = 44/40 = 1.1 g ${{cm}^{3}}$
(ii) The density of tin is higher than that of water, so the sheet of tin sinks in water. But when the same sheet of tin is converted into a boat or box, a lot of air is trapped in the boat or box. Then, the average density of boat or box made of tin sheet becomes lower than that of water.Therefore, it floats in water