"Momentum is the product of velocity and its magnitude." Is this statement true or false?

$A$ $4 \ kg$ disk slides over level ice toward the east at a velocity of $1 \ m/s$,as shown. The disk strikes a post and rebounds toward the north at the same speed. The change in the magnitude of the eastward component of the momentum of the disk is ............. $kg \cdot m/s$.

In a force $F$ versus time $t$ graph for an object,the area enclosed in a time interval of $1 \ s$ is $100 \ Ns$. Calculate the magnitude of the force. (in $N$)

$A$ machine gun fires a bullet of mass $35 \ g$ with a speed of $600 \ m/s$. The person holding the gun can exert a maximum force of $147 \ N$ on it. The number of bullets that can be fired from the gun per second is

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?

$N$ 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: