Rotational Velocity and Acceleration

[PhysicsScrub]

1. Electric toothbrushes can be effective in removing dental plaque. One model consists of a head 1.1 cm in diameter that rotates back and forth through a 70.0 angle 7600 times per minute. The rim of the head contains a thin row of bristles. (See the figure )Assuming that the toothbrush has constant angular acceleration in each of the directions it turns, find the angular acceleration (in rad/sec² ) of the rotating head and the tangential acceleration (in m/s² ) of the bristles.


What is the rotational acceleration in rad/sec²

What is tangental accelration in m/s²

 

[gneill]

Seriously? A toothbrush 1.1 inches in diameter? Is it for horses?

 

[PhysicsScrub]

Seriously? A toothbrush 1.1 inches in diameter? Is it for horses?

Oops. that should say 1.1 cm

 

[gneill]

Oops. that should say 1.1 cm

Phew! You had me worried for a moment there

So assuming that the brush goes from zero to angle seventy degrees in a half period, what is the required angular acceleration?

 

[PhysicsScrub]

Phew! You had me worried for a moment there

So assuming that the brush goes from zero to angle seventy degrees in a half period, what is the required angular acceleration?

realllly unsure bud

 

[gneill]

Well, if it goes back and forth 7600 times every minute, what's the period for one cycle?