How many plank lengths are in 6 feet. Where a plank length is described as 10 to -20 the length of a proton?
A tube is completely full of ping pong balls and is a parsec long with a diameter a plank length wider than that of a ping pong ball. If you take an additional ping pong ball, and push it in one end of the tube, how long would it take for the ball on the other end of the tube to pop out?