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phy121
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.
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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: ->->->->->->->->->->->-> :
we know that the spin force exerted by the 15cm rubber band is 15cm /100 = .15 meters * 3N = .45 newton M
in order to prevent the system from rotating, the rubber band at the 5cm point which is .05 m will need to create a spin force equal to -.45 newton M
to do so
.05 m*F = -.45 Newton m
F =- 9 newtons
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• 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: ->->->->->->->->->->->-> :
once the system is in place the net force would be -9 newtons + 3 newtons = 6 newtons if the glue holding the die comes loose, I would think the system would accelerate in the direction of the net force.
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10 minutes
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&#Very good work. Let me know if you have questions. &#