Answer:21.3%
Explanation:
Given
80 % reduction in tool life
According to Taylor's tool life
[tex]VT^n[/tex]=c
where V is cutting velocity
T=tool life of tool
80 % tool life reduction i.e. New tool Life is 0.2T
Thus
[tex]VT^{0.12}=V'\left ( 0.2T\right )^{0.12}[/tex]
[tex]V'=\frac{V}{0.2^{0.12}}[/tex]
[tex]V'=\frac{V}{0.824}[/tex]=1.213V
Thus a change of 21.3 %(increment) is required to reduce tool life by 80%
