Question

I solid is composed of a cylinder with hemispherical ends. If the whole length of solid is
100cm and the diameter of the hemispherical ends is 28cm. Find the cost of polishing the
surface of the solid at the rate of 5 paise per sq.cm.​

Answer 1

In the given solid height of cylinder = 100 - 2{radius of hemisphere} = 100 - 28 = 72

CSA of the solid = CSA of cylinder + CSA of both hemispheres

= 2*22/7*14*72 + 2 { 2*22/7*14*14 }

= 8800cm2

Cost = 8800 * .05 = Rs 440

Answer 2

Let's first find the total surface area of the solid. The solid consists of a cylinder and two hemispheres.

Radius of hemispherical ends = Diameter/2 = 28/2 = 14 cm

Height of cylinder = Total length - 2 * radius of hemispherical ends = 100 - 2 * 14 = 72 cm

Total surface area of solid = Curved surface area of cylinder + 2 * Curved surface area of hemisphere + 2 * Area of circular bases

Curved surface area of cylinder = 2πrh = 2 * π * 14 * 72 = 20160π sq. cm

Curved surface area of hemisphere = 2πr^2 = 2 * π * 14^2 = 1232π sq. cm (for one hemisphere)

Area of circular base = πr^2 = π * 14^2 = 196π sq. cm

Total surface area of solid = 20160π + 2 * 1232π + 2 * 196π = 24576π sq. cm

Now, the cost of polishing the surface of the solid at the rate of 5 paise per sq. cm would be:

Cost = 24576π * 5/100 = 1228.8π/100 = Rs. 38.56 (rounded to two decimal places)

Therefore, the cost of polishing the surface of the solid at the given rate would be Rs. 38.56.

Learn more about area :

https://brainly.in/question/14759304

Learn more about diameter :

https://brainly.in/question/1737906

#SPJ2