A few questions i don't understand on the huge holiday assignment for the three day weekend. 1) Why are most mountain roads designed so that they weave back and forth with a gradual slope rather than going straight uphill. 2) What are the work-energy transformations involved in throwing a ball upward. 3) What is the work-energy conversion which occurs when a crane lifts a heavy crate from the ground to the top of a three-story building? 4) What happendes to the energy when a moving car hits a brick wall and comes to rest? 5) What happens to the work expended by a boy pulling a sled across the ice of a frozen pond? 6) What has happened to the energy of a ball rolling across the floor as it comes to a stop. If you could answer any of these I would greatly appreciate it. Some of you will think that I am asking for last minute homework help. The answer is I am not. I am just interested in the answers to the questions. Thanks again.