Question

marble of diameter 1.4 CM are dropped into a beaker containing some water and a fully submerged the diameter of the bigger is 7 cm find how many medals have been dropped in it if the water rises by 5.6 CM

Answer 1

diameter of marble = 1.4 cm

radius = 1.4/2 = 0.7 cm

volume of 1 marble =

4/3 πr ^3 =4/3 A ×π × (0.7 ) ^3

let number of marbles required = n

base diameter of beaker = 7cm

radius = 7/2 = 3.5 cm

height rise in water = 56 cm

volume change = volume of n marbles

π r^2h =n × 4/3 ×π × (0.7 )^3

n= π ×3.5^2 ×56

---------------------------- =3.5 ^2 ×56 ×3

(4/3 ) ×π ×(0.7 )^3 ---------------------

4 × 0.7 ^3

= 1500

So 1500 marbles should be dropped.