Phy 201

The situation here is similar to that depicted above, though the distances of the rubber

bands from the center are different. The die on which the strap rotates is not visible, but

is attached to the tabletop; the blue push pin constrains the system to rotate about a

vertical axis through the center of the die.

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:

9 netwons. If you multiply the the F*`ds you get 3newtons *15cm= 45N cm. If you divide 45N

cm by 5cm= 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:

It should pull toward you at the same position

5min