$N$ number of balls,each of mass $m \ kg$,moving along the positive direction of the $x$-axis,strike a wall per second and return elastically. The velocity of each ball is $u \ m/s$. The force exerted on the wall by the balls in newtons is:

The magnitude of force acting on a particle moving along the $x$-axis varies with time $(t)$ as shown in the figure. If at $t=0$ the velocity of the particle is $v_0$,then its velocity at $t=T_0$ will be

Two particles of masses $m_1$ and $m_2$ in projectile motion have velocities $\vec{v}_1$ and $\vec{v}_2$ respectively at time $t = 0$. They collide at time $t_0$. Their velocities become $\vec{v}_1'$ and $\vec{v}_2'$ at time $2t_0$ while still moving in air. The value of $|(m_1\vec{v}_1' + m_2\vec{v}_2') - (m_1\vec{v}_1 + m_2\vec{v}_2)|$ is

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?

Which force acts on a body first: action or reaction?

$A$ body of mass $50 \, g$ has a velocity of $20 \, cm/s$. If a constant force of $50 \, dyne$ acts on it,what will be its momentum after $5 \, s$?