April 2015 stories at the main FCP site

The April 2015 stories at the main FCP site: (1) I spent many hours trying to work out the operation of this simplistic electric train that only recently appeared on YouTube: Attach magnets at the two ends of a common AA or AAA battery. Insert the assembly (the “train”) into a copper-wire coil. The train shoots through the coil. If you make a loop out of the coil, the train will shoot around the loop for hours. What in the world propels the train? (2) Pour pepper onto salt. Can you then separate the two types of grains? That is the pub challenge this month. (3) Whispering park benches --- a friend whispers at one end of this long bench and you can then clearly hear the words at the far end. This is the park version of the famous whispering gallery of St. Paul’s Cathedral in London. (4) When the flying bombs (V1) were sent into England in World War II, some English pilots were able to disrupt the gyroscopic guidance of the bombs by bring their wing down onto the flying bomb’s wing.

The Flying Circus of Physics