a bucket made up of metal sheet is in the form of a frustum of a cone of height 16 cm with radii of its lower and upper ends as 8 cm and 20 cm respectively. find the cost of the bucket if the cost of the metal sheet is Rs. 15 per 100 cm3 ( use pi= 22/7)
Height of the bucket, h = 16 cm (Given)
Let the radii of the upper and lower ends of the bucket be r1 and r2 respectively.
Given, r1 = 20 cm and r2 = 8 cm.
Surface are of bucket
= Curved surface area of the bucket + Area of base of the bucket
= π(r1 + r2)l + πr22
= π [ (r1 + r2)l + r22 ]
= [ (20 cm + 8 cm) 20 cm + (20 cm)2 ]
= (28 × 20 cm2 + 400 cm2)
= ( 560 cm2 + 400 cm2 )
= × 960 cm2
= 3017. 14 cm2 (Approx)
Given, cost of 100 cm2 metal sheet = Rs 15
Thus, the cost of the bucket is approximately Rs 452.60.