Two blocks A and B of mass 10 kg and 20 kg respectively are placed as shown in figure. Coefficient of friction between all the surfaces is 0.2 (g = 10m /s² ) . Then

free body diagram of A and B is

For A
T cos30⁰ =N
T sin 30⁰ = 0.2N +100
Solving these two equations we get
T $\approx$ 306 Newton and N $\approx$265 Newton
For B
$\mathrm{a}=\frac{{\mathrm{m}}_{\mathrm{B}}\mathrm{g}-0.2\mathrm{N}-0.2\mathrm{N}}{{\mathrm{m}}_{\mathrm{B}}}=\frac{200-0.4\left(265\right)}{20}=4.7\mathrm{m}/{\mathrm{s}}^2$