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

$A$ golf ball of mass $50 \text{ g}$ placed on a tee is struck by a golf club. The speed of the golf ball as it leaves the tee is $100 \text{ m/s}$, and the time of contact with the ball is $0.02 \text{ s}$. If the force decreases to zero linearly with time, then the force at the beginning of the contact is (in $\text{ N}$)

$A$ particle of mass $1\, kg$ is acted upon by a force $F$ which varies as shown in the figure. If the initial velocity of the particle is $10\, ms^{-1}$, the maximum velocity attained by the particle during the period is ........ $ms^{-1}$.

$A$ force of $50 \text{ dynes}$ acts on a body of mass $5 \text{ g}$ which is at rest for an interval of $3 \text{ seconds}$. The impulse is:

If a force of $250\, N$ acts on a body,the momentum acquired is $125\, kg \cdot m/s$. What is the period for which the force acts on the body? ......... $s$

$A$ cannon after firing recoils due to