High five! - cyclists rotation · Physics Brawl 2015 #FoL.6
Physics · mechanics
Problem
Tomáš and Michal have met on a cycleway and want to high five while riding. Both of them have the same mass m=70kg, speed v=8m⋅s−1 and their arms are stretched horizontally at a distance of l=1m from the centres of mass of their bodies. They are moving along parallel lines, but in opposite directions. The distance between their centres of mass at the moment when they are passing by is exactly 2l. Determine the frequency (in Hz) with which they would rotate around their common centre if they grabbed each other's hands. Neglect the mass of their bicycles and energy loss during the act of catching each other. Consider the cyclists to be mass points.