Question

A solid is composed of a cylinder with hemispherical ends. If the whole length of th solid is 104 cm and the radius of each of the hemispherical ends is 7 cm, find the cos of polishing its surface at the rate of 10 per dm?. ICBSE 2006 blocsolof diameter 14 cm and height 42 cm is fixed symmetrically inside​

Answer 1

Answer:

Cost of polishing the solid=Rs.183.04.

Step-by-step explanation:

Hemispherical part: r=7cm

Cylindrical part: r=7cm,h=104−(7+7)=90cm

Total surface area of the solid= CSA of cylindrical part+2×CSA of hemispherical part

=2πrh+2×2πr^2= 2πr(h+2r)

2× $\frac{22}{7\\}$×7[90+2(7)]$cm^{2}$

44×104$cm^{2}$=4576$cm^{2}$

TSA of the solid=4.576$cm^{2}$

Cost of polishing at the rate of Rs.4 per 100$cm^{2}$

=4576×$\frac{Rs.4}{100}$=Rs.183.04

Cost of polishing the solid=Rs.183.04.