Physics 113 –Morning 2006

Extra credits problems #4

Team #______________

Member 1__________________

Member 2__________________

Member 3__________________

Rules:

-Collaboration between team members is encouraged, however one or two authors will be responsible for one problem and may be asked to explain it.

-The authors should present the solution on a blank sheet with their names on it

-Solutions should include “self-explained” diagrams/sketches, with minimal wording. Neat presentation will count toward the problem grading.

1.- Design a method to separate marbles from tennis balls by making use of rolling motion and conservation laws.

2.- Estimate the location of a circular hole on a disk (r_hole ≈ r_disk/10) if you apply a force F=100N tangential to the disk, it rotates at ω=5 rpm.

3.- Using conservation of angular momentum, by holding a bike wheel (mass m, radius r) on a circular platform (free to rotate about its center, a disk of mass M and radius R), describe a method to measure your mass using a stopwatch (a funny balance!).