Two uniform solid spheres, Sphere 1 and Sphere 2, are released from rest at the top of an incline that makes an angle \(\theta\) with the horizontal. Sphere 1 has mass \(M_1\) and Sphere 2 has mass \(M_2\), where \(M_1 = 2M_2\). Both spheres have the same radius \(R\) and roll down the incline without slipping. What is the ratio \(a_1/a_2\) of the linear acceleration of the center of mass of Sphere 1 to that of Sphere 2?