PHYSICS 7A Study Guide - Midterm Guide: Free Body Diagram, Friction, Angular Velocity
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Physics 7a, spring 2018, sections 2 and 3, instructor: professor adrian lee. Show your reasoning carefully so that we can be sure that you derived the answer rather than guessing it or relying on memory; in addition, this enables us to give partial credit. You may use one double-sided 3. 5 x 5 index cards of notes. Answers should be a short paragraph only, perhaps with a drawing, and very little, if any, math: a mass m is suspended by a string from the ceiling. A second string is attached to the bottom of the mass and pulled. If the bottom string is pulled slowly (slow build up of force and hardly moving) which string breaks. [5 pts. : give a simple explanation for why the static coe cient is usually higher than the kinetic coe cient of friction. 2 trajectory problems [25 pts. total: a falling stone takes time tw to travel past a window of height h (see gure).
