Two blocks 4 kg and 2 kg are sliding down an inclined plane as shown in the figure. The acceleration of 2kg block is_____

$4\text{g}\sin \theta -{\text{f}}_{\text{1}}=4\text{a}\to \left(1\right)$

$2g\sin \theta -{\text{f}}_{\text{2}}=2\text{a}\to \left(2\right)$

$6g\sin \theta -{\text{f}}_{\text{1}}-{\text{f}}_{\text{2}}=6\text{a}$

$\text{6gsin}\theta -\text{0}\text{.3}\times \text{40}\times \frac{\sqrt{3}}{2}-0.2\times 20\times \frac{\sqrt{3}}{2}=6\text{a}$

$\text{30}-\text{6}\sqrt{3}-2\sqrt{3}=6\text{a}$

$\text{30}-\text{8}\sqrt{3}=6\text{a}$

$\text{a}=\text{2}\text{.66}{\text{m/s}}^2$