\(m_{1} g-T_{1}=m_{1} a\) \(...(I)\)
\(T_{2}-m_{2} g=m_{2} a\) \(...(II)\)
\(T_{1} R-T_{2} R=I \alpha\)
\(=\frac{M R^{2}}{2} \cdot \frac{a}{R^{2}}\)
\(T_{1}-T_{2}=\frac{M a}{2}\) \(...(III)\)
Add equation \((I), (II),\) and \((III).\)
\(m_{1} g-m_{2} g+T_{2}-T_{1}=\left(m_{1} a+m_{2} a\right)\)
\(10-5=\frac{2 a}{2}+\frac{a+a}{2}\)
\(5=\frac{5 a}{2}\)
\(a=2 \neq\)