1. Science is the belief in the ignorance of experts. -- Richard Feynman

2. Statics and Dynamics Problem Solving 1.Make a sketch if none given 2.Make FBDs 3.Choose coordinate axes (wisely!) 4.Write for each direction and each mass 5.Check that you have enough equations! 6.Solve Note: massless ropes have same tension everywhere! (Memorize this fact!) In dynamics problems, you may have to use

3. Friction

5. What is the tension in rope 1 if the angle  1 = 90° (and  2 is not 90°) ? A] 0 B] mg/2 C] mg D] can’t tell.

6. Is there some angle so that, if you push at a higher angle (more downward), you can never move the block, no matter how hard you push? A] yes, if there is friction with the floor B] yes, if there is no friction with the floor C] A & B both D] no