Action and reaction forces act on

The force-time $(F-t)$ curve of a particle executing linear motion is as shown in the figure. The momentum acquired by the particle in the time interval from $0$ to $8 \ s$ will be ........... $N-s$.

$A$ ball of mass $0.1 \, kg$ coming with a speed of $30 \, m/s$ strikes a bat and returns in the opposite direction with a speed of $40 \, m/s$. Calculate the impulse. (Take the final velocity as positive.)

Consider the following statement: When jumping from some height,you should bend your knees as you come to rest,instead of keeping your legs stiff. Which of the following relations can be useful in explaining the statement?

$A$ particle moves in the $x-y$ plane under the action of a force $\overrightarrow{F}$ such that the value of its linear momentum $\overrightarrow{P}$ at any time $t$ is $P_x = 2\cos t$ and $P_y = 2\sin t$. The angle $\theta$ between $\overrightarrow{F}$ and $\overrightarrow{P}$ at a given time $t$ will be $\theta = $ ........... $^o$.

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