A mass 0.9 kg , attached to a horizontal spring, executes SHM with an amplitude $\mathrm{A}_1$. When this mass passes through its mean position, then a smaller mass of 124 g is placed over it and both masses move together with amplitude $A_2$. If the ratio $\frac{A_1}{A_2}$ is $\frac{\alpha}{\alpha-1}$, then the value of $\alpha$ will be $\_\_\_\_$ .