SOLUTION: From a cylindrical object of diameter 70cm and height 84cm a right solid cone having is base as one of circular ends of the cylinder and with height 84cm is removed.calculate the a

Algebra ->  Volume -> SOLUTION: From a cylindrical object of diameter 70cm and height 84cm a right solid cone having is base as one of circular ends of the cylinder and with height 84cm is removed.calculate the a      Log On


   

Question 1166470: From a cylindrical object of diameter 70cm and height 84cm a right solid cone having is base as one of circular ends of the cylinder and with height 84cm is removed.calculate the area of the remaining solid object and calculate the remaining solid object (take pia radius to be 22/7)
Found 2 solutions by mananth, ikleyn:
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
From a cylindrical object of diameter 70cm and height 84cm a right solid cone having is base as one of circular ends of the cylinder and with height 84cm is removed.calculate the area of the remaining solid object and calculate the remaining solid object (take pia radius toOOps
Deleted as error pointed out by@Ikleyn. Thanks

Answer by ikleyn(52799) About Me  (Show Source):
You can put this solution on YOUR website!
.
From a cylindrical object of diameter 70cm and height 84cm a right solid cone having its base
as one of circular ends of the cylinder and with height 84cm is removed.
calculate the area of the remaining solid object (take pia radius to be 22/7)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


        Calculations of the area in the post by @mananth are  INCORRECT,
        since he includes the base area thrice and subtracts the lateral area of the cone,
        while it should be added.

        I came to provide correct calculations. 


Surface area of the remaining solid consists of three parts: the base of the cylinder,
the lateral surface area of the cylinder and the lateral surface area of the cone.


Area of the base             = pi%2Ar%5E2   = %2822%2F7%29%2A35%5E2    =  3850 cm^2.

Lateral area of the cylinder = 2%2Api%2Ar%2Ah = 2%2A%2822%2F7%29%2A35%2A84 = 18480 cm^2.

Lateral area of the cone     = pi%2Ar%2AL   = %2822%2F7%29%2A35%2Asqrt%2835%5E2%2B84%5E2%29 = 10010 cm^2.


Now the surface area of the remaining solid is  the sum

    3850 + 18480 + 10010 = 32340 cm^2.    ANSWER

Solved (correctly).