Question

the internal and external diameter of a low hemisphere vessel are 20 cm and 28 cm respectively.find tge cost of painting the vessel all area at 14 paints/cm​

Answer 1

Answer:

Rs. 302.7192

Step-by-step explanation:

Given : internal diameter = 20 cm

external diameter = 28 cm

Therefore internal radius; R= 10cm

External radius; r= 14 cm

Total surface area= curved surface area of internal hemisphere + curved surface area of outer hemisphere + area of ring

Now as we know Curved surface area of hemisphere is

Now curved surface area of internal hemisphere is

Now curved surface area of outer hemisphere

area of ring = area of outer circle -area of inner circle

(i)+(ii)+(iii) we get

Total surface area= curved surface area of internal hemisphere + curved surface area of outer hemisphere + area of ring = 1232+ 628.57+ 301.71 = 2162.28cm²

Cost of per cm² = 14p

cost of 2162.28cm²= 14 x 2162.28=30271.92p = Rs. 302.7192

Hence, the cost of painting the vessel is Rs. 302.7192

hope it helps