A rigid ball of mass m strikes a rigid wall at $60°$ and gets reflected without loss of speed as shown in the figure below. The value of impulse imparted by the wall on the ball will be:- 
 

In the following diagram find value of $T_2$.

If $m_1=m_2=1 \mathrm{kg}$ then find out the distance travelled by $m_1$ in the first $\frac{1}{2}$ second. 

Two blocks $A$ and $B$ of masses $3m$ and $m$ respectively are connected by a massless and inextensible string. The whole system is suspended by a massless spring as shown in the figure. The magnitudes of acceleration of $A$ and $B$ immediately after the string is cut, are respectively:-

Force of $3 \mathrm{N}$ acts on a system of two blocks of mass $2 \mathrm{kg}$ and $1 \mathrm{kg}$ as shown in the figure. The contact force between the blocks is:
 

If the string is pulled with the acceleration of $2 \mathrm{m} {\mathrm{s}}^{-2}$, then the acceleration of the block is