$3.)$ Find out the approximate time required to machine a hole of diameter equal to $6\mathrm{.}0$ mm

in a tungsten carbide plate $($fracture hardness $=6900\frac{N}{m}{m}^2=6\mathrm{.}9{10}^9\frac{N}{m^2})$ of

thickness equal to one and half times of hole diameter. The mean abrasive grain size

is $0\mathrm{.}015$ mm diameter. The feed force is equal to $3\mathrm{.}5$ N $.$ the amplitude of tool

oscillation is $25m$ and the frequency is equal to $25$ kHz $.$ The tool material used is

copper having fracture hardness equal to $1\mathrm{.}5103\frac{N}{m}{m}^2.$ The slurry contains one

part abrasive to one part of water. Take the values of different constants as $K1=0\mathrm{.}3,$

$K2=1\mathrm{.}8m{m}^2,K3=0\mathrm{.}6,$ and abrasive density $=3\mathrm{.}8\frac{g}{c}{m}^3.$

Also calculate the ratio of the volume removed by throwing mechanism to the volume

removed by hammering mechanism.