Question

A metal rod is 7 metering long ,the cross section has inner diameter 2m and outer diameter 2.2 m .find the cost of painting the pipe from both sides at the rate of ₹10 per sq m

Answer 1

Answer:

Total cost = ₹1848

Step-by-step explanation:

L= 8m

$R_{i}$= 2m

$R_{o}$= 2.2m

Outer CSA = 2×π×$R_{o}$×L

                  = 2×$\frac{22}{7}$×2.2×7

                  = 2×22×2.2

                  = 96.8$m^{2}$

Inner CSA = 2×π×$R_{i}$×L

                 = 2×$\frac{22}{7}$×2×7

                 =2×22×2

                 = 88$m^{2}$

Total are to be painted = Outer CSA + Inner CSA

                                       = 96.8 + 88

                                       = 184.8$m^{2}$

Total cost of painting = 184.8 × 10 Rs.

                                    = ₹ 1848