The internal and external diameters of a hollow hemispherical vessel are 14 cm and 21 cm respectively. The cost of silver plating of 1 sq. cm of its surface is Rs 1.60. Find the total cost of silver plating the vessel all over.
3 Answers | Add Yours
The hemispherical vessal has two surfaces. Internal and external.
Let R and r be the eadius of the internal and external radius. Also radius is half the diameter.
The outer surface area of the hemisphere = (1/2)( 4*pi*R^2 ) =2 pi*(21/2)^2 = 2770.88472/4 sq cm = 692.72118
The area of the internal hemisphere = (1/2)*(4pir^2) = 2pi*r^2 = 2pi*(14/2)^2 = 1231.50432/4 sq cm = 307.8760801 sqcm
The ring or edge area = pi *R^2-Pir^2 = pi*(R^2-r^2) = pi*(21^2-14^2)/4 =769.6903001/4 = 192.422575 .
Thererefore the total area = 692.72118+307.87608+192.422575 = 1193.019835 sq cm
Therefore the plating cost @ Rs 1.60 for the above total area = 1193.019835 sq cm * Rs1.6sqcm = Rs 1908.83
Hi, for any homework help, assignment help, dissertation help, visit our website http://www.helpwithassignment.com. We offer online tutoring, assignment help, homework help, dissertation help and thesis help in almost all the subjects. We offer services for a range of subjects for K-12, College and University.
This is a basic math problem if you are facing trouble solving this than you should hire one of the online math tutors available on internet.At this students can submit their questions online to get the answers. They can also get elaborate explanations on particular topics required from the tutors. The students can observe the solved examples online and solve similar problems. They can also clarify their doubts regarding the concepts involved from the tutors immediately.
Join to answer this question
Join a community of thousands of dedicated teachers and students.Join eNotes