Tool life in the case of a grinding wheel is the time

Q. A grinding wheel $A27K7V$ is specified for finished grinding of a $HSS$ cutting tool. What do you understand about the wheel from the abvoe code. Is this an appropriate choice?

Q. Coefficient of friction between a tool and grinding wheel is $\mu$. Power developed in watt by the wheel of radius r running at n revolutions per second when tool is pressed to the wheel with F' kgf is

Q. A grinding machine whose wheel has a radius of $1/\pi$ is rotating at $2.5rev/sec$ A tool to be sharpened is held against the wheel with a force of $40N$. If the coefficient of friction between the tool and wheel is $0.2$, power required is:

Q. A grinding machine whose wheel has a radius of $\frac{1}{\Pi }$ is rotating with angular speed at 2.5 rev/sec. A tool to be sharpened is held against the wheel with a force of 40N. If the coefficient of friction between the tool and the wheel is 0.2, power required is

Q. During grinding of a C.I specimen of 10 mm wide and 100 mm long with A 27 K 6V grinding wheel of 300 mm dia and 25 mm wide, the wheel has undergone a radial wheel wear of 50 microns after removing a layer of 5 mm. The grinding ratio is