# Solve the following :

Question:

A ceiling fan has a diameter (of the circle through the outer edges of the three blades) of $120 \mathrm{~cm}$ and rpm 1500 at full speed. Consider a particle of mass $1 \mathrm{~g}$ sticking at the outer end of a blade. How much force does it experience when the fan runs at full speed? Who experts this force on the particle? How much force does the particle exert on the blade along its surface?

Solution:

Radius of the circle $=\frac{120}{2} \mathrm{~cm}=60 \mathrm{~cm}$

Angular speed=1500rpm

$\omega=1500 \times \frac{\frac{2 \pi}{60}}{}$

Force $=m R \omega^{2}$

$=\left(\frac{1}{1000}\right)$ $(0.6)(157)^{2}$

$F=14.8 \mathrm{~N}$