posted by Ann .
A ventilation fan has blades 0.25 m in radius rotating at 20rpm. What is the tangential speed of each blade tip?
i don't understand how to do tangential speed.
The tip travels 2*pi*0.25*20 meters (in a circle) in 60 seconds.
That is a tangential speed of 0.524 m/s
Are you sure the rotation rate is only 20 rpm? That is VERY slow for a fan.
20 rev/second is more likely for a ventialation fan.