Page 88 - WCS - Electrical
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WORKSHOP CALCULATION & SCIENCE - CITS



                                               4   22
                                                 x    x r³   = 15625
                                               3   7
                                                        15625 x 3 x 7
                                               r³     =
                                                           4 x 22
                                                        328125
                                                      =
                                                           88
                                                      = 3728.69
                                                        3
                                               r      =    3728.69
                                                      = 15.51 cm
                                                  diameter  = 2 x radius

                                                      = 2 x 15.51
                                                      = 31.02 cm
           3  How many spherical balls of 1 cm radius can be made from a sphere of 32 cm diameter.
                 No. of balls x volume of small sphere = Volume of bigger sphere
                                           4        4   4
                                         N x   x  r³    =    r³
                                           3        3   3
                                            4   4       4
                                         N x   x   x 1³  =   x   x r3
                                            3   3       3
                                         N            = 16 x 16 x 16
                                                      = 4096 balls

           4  Three brass balls of diameters 3 cm, 4 cm and 5 cm are melted and make into one solid ball, if there is no
              wastage. Find the diameter of the solid ball.
                                         1  ball d1   = 3 cm,
                                         st
                                                      r1    = 1.5 cm
                                         2  ball d2   = 4 cm,
                                         nd
                                                      r2    = 2 cm
                                         3  ball d3   = 5 cm,
                                         rd
                                                      r1    = 2.5 cm
                                         Diameter of new ball = ?

                                       Volume of new ball = Volume of 3 spherical balls
                                              4         4       4      4
                                                       r3  =   r1³  +    r2³ +    r3³
                                              3         3       3      3
                                              4         4
                                                      r³   =     (1.53 + 23 + 2.5)3
                                              3         3
                                                         r³   = 3.375 + 8 + 15.625
                                                         r³   = 27

                                                         r   =
                                                        3
                                                         r   =   3x3x3

                                                         r   = 3 cm



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                                            CITS : WCS - Electrical - Exercise 6
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