In Newtonian mechanics,which parameter is changed by the application of an external force?

If two balls each of mass $0.06 \,kg$ moving in opposite directions with speed $4 \,m/s$ collide and rebound with the same speed,then the impulse imparted to each ball due to the other is ........... $kg \cdot m/s$.

Which type of forces are responsible for the explosion of a chemical bomb: internal or external forces?

The figure shows the position-time graph of a particle of mass $4 \,kg$. What is the
$(a)$ force on the particle for $t < 0$,$t > 4 \,s$,and $0 < t < 4 \,s$?
$(b)$ impulse at $t = 0$ and $t = 4 \,s$? (Consider one-dimensional motion only).

$A$ body of mass $m_1$ exerts a force on another body of mass $m_2$. If the magnitude of acceleration of $m_2$ is $a_2$,then the magnitude of the acceleration of $m_1$ is (considering only two bodies in space).

In the figure shown,a balloon is pressed against a wall. It is in equilibrium and maximum compressed state. $\vec F_1 =$ force of balloon on hand of man; $\vec F_2 =$ force of balloon on wall; $\vec F_3 =$ friction; $\vec F_4 =$ weight of balloon. Choose the correct statement.