# Angular Speed of a Pencil

A pencil, 15.7 cm long, is released from a vertical position with the eraser end resting on a table. The eraser does not slip. Treat the pencil like a uniform rod. What is the angular speed of the pencil just before it hits the table?

a) 13.7 rad/s

b) 7.23 rad/s

c) 24.5 rad/s

d) 16.8 rad/s

https://brainmass.com/physics/energy/angular-speed-pencil-116775

#### Solution Preview

A uniform rod of mass M and length r rotating about its end has a moment of inertia:

I = 1/3* M*r^2

The kinetic energy of rotation with angular speed w ...

#### Solution Summary

The solution calculates the angular speed of a dropped pencil.

$2.19