I'm having trouble figuring these 2 problems out: 4000cm^3 (.004m^3) of oil is spilled onto a smooth lake. If the oil spreads out uniformly until it makes an oil slick 3 molecules thick, with adjecent modlecules just touching, estimate the diameter of oil slick. Assume the oil molecues have diameter of 2x10^-10. The other problem is: A bowling ball traveling with constant speed hits the pins at the end of a bowling land 16.5m long. The bowler heas the sound of the ball hitting the pins 2.70 seconds after the ball is released form his hands. What is the speed of the ball? The speed of sound is 340m/s. Any hints on how to get started would be greatly appreciated. Thanks in advance.