Mistical: My friend here in Kenya uses a piece of cloth, soaked in a washing detergent to wipe the inside of his vehicle鈥檚 wind screen whenever it rains. This prevents the windscreen from becoming misty even if the windows remain closed. Why does this work?
Gung-ho guns: In many parts of the world, people celebrate victories birthdays and similar events by firing guns into the air with great exuberance and a seeming disregard for the welfare of themselves and others. Assuming the barrel of the gun is perpendicular to the ground when the bullet leaves it, approximately what altitude would it reach and what is its velocity (and potential lethality) when it falls back to Earth?