cq_1_201

phy201

Your 'cq_1_20.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.

** **

The problem:

The metal strap used in the Angular Velocity of a Strap experiment is constrained by a vertical push pin to rotate about a hole in a

die. The die is glued in place to a massive tabletop. A rubber band is attached to a point 15 cm from the axis and stretched so that

it exerts a force of 3 Newtons, directed perpendicular to the rod. If this force is unopposed it will accelerate the system rapidly.

You want to attach a second rubber band 5 cm from the axis to prevent the system from rotating.

How much force will that rubber band have to exert?

answer/question/discussion: ->->->->->->->->->->->-> :

15cm = 3N

5cm=?N

tau= f* r

tau = 3N * .15m= .45

.45= N * .05cm

n= 9N

#$&*

Once both of these forces are in place and the system is stationary, what (if anything) will happen if the glue holding the die to the

tabletop comes loose?

answer/question/discussion: ->->->->->->->->->->->-> :

The strap will move in the direction of force of the rubber bands.

#$&*

--------------------------------------------------------------------------------

Copy and paste your work into the box below and submit as indicated:

** **

about 20 mins

** **

&#Very good responses. Let me know if you have questions. &#