$($c$)$ Through holes $10$ mm diameter; $15$ mm depth are drilled in a MS workpiece using HSS twist drill. The

rill has a point angle of $120.$ An experiment was conducted in the machine shop to study the effect of cipindle

$L*PM(N)$ on the number of holes $($H$)$ produced before the tool change using axial feed of $0\mathrm{.}2m\frac{m}{r}ev$ and the

results are written in the table below:

Divelop Taylor's tool life equation and another tool life equation between H and N from the above data. $(6)$

$($d$)$ A hole is to be drilled in a block of aluminium alloy having specific cutting energy of $2000\frac{N}{m}{m}^2$ using