Two curling contestants dispute possession of a stone of mass 17.7 kg. The mass of contestant A is 57.5 kg, whereas that of contestant B is 111.4 kg. Contestant A pulls on the stone with a horizontal force of 17.3 N, but is unable to break contestant B's grip. The result is a stalemate (the stone does not accelerate).
a. Neglecting (for now) frictional forces between the stone and the ice, what is the horizontal force that contestant B exerts on the stone? [Note: Indicate a pull (a force in contestant B's direction) by a positive sign and a push (a force in contestant A's direction) by a negative sign.]
b. What is the minimum coefficient of static friction required between the contestants and the ice (assume that it is the same for both contestants)?