A body of mass $$10 \mathrm{~kg}$$ is kept on a horizontal surface. The coefficient of kinetic friction between the body and the surface is 0.5. A horizontal force of $$60 \mathrm{~N}$$ is applied on the body. The resulting acceleration of the body is about

Two masses of $$5 \mathrm{~kg}$$ and $$3 \mathrm{~kg}$$ are suspended with the help of massless inextensible strings as shown in figure below.

When whole system is going upwards with acceleration $$2 \mathrm{~m} / \mathrm{s}^2$$, the value of $$T_1$$ is (use, $$g=9.8 \mathrm{~m} / \mathrm{s}^2$$)