These two pages provide a guide to our quiz from last Friday. This much longer than what you were expected to do on the quiz, and provides some insight into the thinking behind the questions and their solutions.
For the first problem the most important thing was go a nice graph for (b), with labels and scales, and, for (a), to realize that being at the highest point of the motion corresponds to having zero speed, and that it takes 1 second to slow down from 10 m/s to zero under the influence of gravity.
The second problem was a conservation of energy problem and you needed to use P.E.= mgh and the expression for K.E. in terms of m and v.
The third problem(extra credit) involves competing considerations --time of flight and launch speed. [It is analogous to the problem regarding the optimal angle for a cannon..., which is governed by the same considerations (time in the air and horizontal speed).] Identifying those two considerations, and the qualitative nature of their dependence on s, is the key thing for problem 3.
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