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

Two identical billiard balls strike a rigid wall with the same speed but at different angles,and get reflected without any change in speed,as shown in the figure. What is
$(i)$ the direction of the force on the wall due to each ball?
$(ii)$ the ratio of the magnitudes of impulses imparted to the balls by the wall?

$A$ body of mass $5 \,kg$ is moving with a velocity of $\vec{v}=(2 \hat{i}+6 \hat{j}) \,m/s$ at $t=0 \,s$. After time $t=2 \,s$,the velocity of the body is $(10 \hat{i}+6 \hat{j}) \,m/s$. The change in momentum of the body is ......... $kg \cdot m/s$.

$A$ force-time graph for a linear motion is shown in the figure,where the segments are circular. The linear momentum gained between $0$ and $8$ seconds is

$A$ ball of mass $150\,g$ starts moving with an acceleration of $20\,m/s^2$. When hit by a force,which acts on it for $0.1\,s$. The impulsive force is ........ $N-s$.

$A$ ball of mass $0.15 \, kg$ is dropped from a height $10 \, m$,strikes the ground,and rebounds to the same height. The magnitude of the impulse imparted to the ball is $(g = 10 \, m/s^2)$ nearly: (in $kg \cdot m/s$)