a cylindrical tomb 3 5 m in outer radius has a hemispherical roof find the cost of painting the - Maths - Surface Areas and Volumes

Question

a cylindrical tomb 3 5 m in outer radius has a hemispherical
roof find the cost of painting the tomb's exterior at the rate of
rs 2 per m sq if the total height of the tomb is 8 m

Utsav · Accepted Answer

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You can easily observe from the figure that h+r = H where r is the
radius of the hemisphere and cylinder and h is the height of the
cylinder and H is the total height

Now radius = 3 5 mAnd total height = 8mHence height of cylinder =
total height - radius = 8 m -3 5 m =4 5 mNow curved surace area of
the tomb = curved surface area of hemisphere+curved surface area of
cylinderSo curved surface area = 2πr2+2πrh
=2×227×(3 5 m)2+2×227×3 5m×4 5m = 77
m2+ 99 m2= 176 m2Now cost of 1 m2 of painting the exterior walls =
Rs 2Hence cost of painting 253 m2= Rs 2×176 = Rs 352

a cylindrical tomb 3.5 m in outer radius has a hemispherical roof. find the cost of painting the tomb's exterior at the rate of rs 2 per m sq if the total height of the tomb is 8 m