Question

Plastic drum of cylindrical shape is made by melting spherical solid plastic balls of radius 1cm.find the number of balls required to make a drum of thickness 2cm,height 90cm and outer radius 30cm(drum has no lid)

Answer 1

volume of sphere*no. of balls=volume of cyl.
4/3*22/7*1*1*1*no. of balls=22/7*2*2*90
no. of balls=270

Answer 2

Answer:

Number of balls required is 52926.

Step-by-step explanation:

Given : Plastic drum of cylindrical shape is made by melting spherical solid plastic balls of radius 1cm. A drum of thickness 2cm,height 90cm and outer radius 30cm(drum has no lid).

To find : The number of balls required to make a drum?

Solution :

Radius of the sphere = 1 cm.

Volume of the sphere is

$V_s=\frac{4}{3}\times \pi r^3$

$V_s=\frac{4}{3}\times\frac{22}{7}\times 1^3$

$V_s=4.19cm^2$

Drum of thickness 2 cm

Outer radius = 30 cm

Height = 90 cm

Outer radius = radius +thickness

30=radius+2

radius=28 cm

Volume of the cylinder is

$V_c=\pi r^2 h$

$V_c=\frac{22}{7}\times 28\times 28\times 90$

$V_c=221760cm^2$

Number of balls required is

$n=\frac{V_c}{V_s}$

$n=\frac{221760}{4.19}$

$n=52926.01$

Therefore, Number of balls required is 52926.