# 1. Diving boards and platforms offer a nearly ideal opportunityin which to experience the various la

1. Diving boards and platforms offer a nearly ideal opportunityin which to experience the various laws of motion. When you jumpoff the high diving board, you are a falling object and, if you cankeep your presence of mind as you fall, you will be demonstratinglaws of physics. Imagine yourself diving off a platform 10 m abovethe water below. a. If you walk very slowly off the platform, so that you falldirectly downward, roughly how long will it take for you to reachthe water? b. You are part of a bad synchronized diving team with a friend.She walks slowly off the platform and you jump to give yourself amodest initial upward velocity. Who will reach the water first? c. You change partners and now you leave the platformsimultaneously with this new partner. Except he walks slowly offthe platform, while you run off the platform. What direction isyour initial velocity? Who will reach the water first? d. If you walk very slowly off the platform, so that you falldirectly downward, roughly how long will it take for you to reachthe water if you were to fall off a 20 meter board? e. How high would the board need to be for a 175 pound man toreach terminal velocity by the time he hit the water? 2. Advanced skiers turn by sliding the backs of their skisacross the snow. Since the fronts of their skis don’t move much,the skis end up pointed in a new direction. a. The amount of sideways force that a skier must exert on theskis to slide them sideways is proportional to how hard the skispress down on the snow beneath them. Why? b. Less skilled skiers sometimes turn without unweighting—theypush their skis sideways so hard that the skis slide anyway. Thistechnique is exhausting. Why does it require so much work? c. Why is wax used on skis? Why wouldn’t WD-40 work as well asthe wax? What is in WD-40? . . .