Question

Marbles of diameter 1.4 cm are dropped into a cylindrical beaker of diameter 7 cm, containing

some water. Find the number of marbles that should be dropped into the beaker so that the water

level rises by 5.6 cm.






please help me​

Answer 1

Answer:

Let m be the number of marbles needed, Let r1 and r2 be the radii of the marbles and cylindrical beaker respectively.

Marbles

Diameter, 2r1=1.4cm

Radius r1=0.7cm

Cylindrical Beaker

Diameter, 2r2=7cm

Radius, r2=27cm

Let h be the height of the water level raised. Then, h=5.6cm

After the marbles are dropped into the beaker,

Volume of water raised = Volume of nmarbles

⇒πr22h=n×34πr13

Thus, n=4r133r22h

n=4×107×107×1073×27×27×5.6=150

The number of marbles needed is 150.