Two \(5.00-\mathrm{kg}\) carts, one red and the other green, are \(1.00 \mathrm{~m}\) apart on a surface where either cart experiences a constant frictional force of \(5.00 \mathrm{~N}\) when it moves. Throughout the problem, the red cart is pushed with a constant force of \(12.0 \mathrm{~N}\) toward the green one. What is the acceleration of \((a)\) the center of mass before the two carts collide, \((b)\) the red cart before they collide, and \((c)\) the center of mass after their totally inelastic collision?