Question

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

• A. 40 W
• B. 4 W
• C. 8 W
• D. 10 W

Answer 1

The correct option is A 40 W

$F=40Nf=0.2\times F=8NP=fr\omega =8\times \frac{1}{\Pi }\times 2.5\times 2\Pi =40$