There are two gears one with radius r and the other with radius 2.2r. The larger hear is subjected to an external couple of -10 Nm about its axis. Assume that the contatct between the two gears occurs at a single point, and the reaction force between teeth is pperpendicular to the constact area.
a) What couple must be applied to the smaller gear so that the system is a in static equilibrium?
b) if r = 2, what reaction force between the two gears?