If the speed of an object is doubled,then which of the following is true?

$A$ wall is hit elastically and normally by $n$ balls per second. All the balls have the same mass $m$ and are moving with the same velocity $u$. The force exerted by the balls on the wall is

$A$ particle of mass $m$, initially at rest, is acted upon by a variable force $F$ for a brief interval of time $T$. It begins to move with a velocity $u$ after the force stops acting. The graph shows $F$ as a function of time, where the curve is a semicircle with peak force $F_0$ at time $T/2$.

$A$ particle of mass $m$ strikes elastically on a wall with velocity $v$,at an angle of $60^{\circ}$ from the wall. The magnitude of the change in momentum of the particle along the wall is:

$A$ particle of mass $m$ moving with velocity $(3\hat{i} + 2\hat{j}) \ m/s$ collides with another body of mass $M$ and finally moves with velocity $(-2\hat{i} + \hat{j}) \ m/s$. Then during the collision:

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