Question

An electric fan has blades of length 30 cm as measured from the axis of rotation. If the fan is rotating at 1200 r.p.m. The acceleration of a point on the tip of the blade is about:

Options

• 1600 m/s²

• 4740 m/s²

• 2370 m/s²

• 5055 m/s²

Answer 1

4740 m/s²

Explanation:

Since, a = ω² r

f = 1200 rpm

Now, converting in second

and f = `1200/60`

= 20 `"rad"/"sec."`

Angular velocity of particle

ω = 2πf

= 20 × 2π = 40π

Now acceleration (a) = ω² r

= (40π)² × `30/100`

= 4740 m/s²