Physics 113 –2007

Extra credits problems #5

Due July 1, 2008

Team #______________

Member 1__________________

Member 2__________________

Member 3__________________

 

Rules:

-Collaboration between team members is encouraged,

-The authors should present the solution on a blank sheet with their names on it. Members of a team should submit together. No credit awarded for separate submissions

-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.- Explain why a helicopter has two helices, what is each for. Explain how to distinguish between a cooked and a raw egg, explain why (the eggs need to be at all point on a flat surface without breaking).

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!).