18. one point, from Lectures 17 and 18, explanations, pictures, possibly an equation in one of the explanations

(a) .3 The Famous Gamma Factor. Define the gamma factor in an equation (.1), with a right triangle (draw it carefully, and label all three sides) (.1), and by drawing a graph of it (.1). See page 95 of March's book for help with the gamma factor graph. Be sure you draw the graph carefully and label key values.

(b) .2 New Rule What is the new rule for ``hard'' and ``soft'' catches for light? (.1) How does the second postulate imply this rule? (.1)

(c) .2 Nature's Speed Limit. How does the second postulate imply that nothing can travel faster than the speed of light? (.2)

(d) .3 Measuring Moving Length. Using a set of 3 pictures of the moving eraser example, carefully labeled, to show incorrect and correct measurements of moving length. (.3)

Revised October 19, 1997.