Three blocks of masses $m_4\text{,} m_2$ and $m_3$ are connected by massless strings as shown on a frictionless table. They are pulled with a force, $T_3=40 \mathrm{N}$. If $m_1=10 \mathrm{kg}\text{,}{ m}_2=6 \mathrm{kg}$ and $m_3=4{ \mathrm{kg}}_{\mathrm{s}}$, the tension $T_2$ will be,

The ratio of the weight of a man in a stationary lift & when it is moving downward with uniform acceleration $a$ is $3:2$ . The value of $a$ is ($g=$acceleration due to gravity)

A block is kept on a frictionless inclined surface with an angle of inclination '$\alpha$'. The incline is given an acceleration '$a$' to keep the block stationary. Then $a$ is equal to 

A wedge is moving with an acceleration, $a=4 \mathrm{m} {\mathrm{s}}^{-2}$ vertically up as shown in figure. What is acceleration of a block of mass $1 \mathrm{kg}$ w.r.t. wedge and normal reaction by wedge on block, respectively. All surfaces are smooth and $\theta =30°$. Choose the correct pair $\left(g=10 \mathrm{m} {\mathrm{s}}^{-2}\right)$.