$A$ body is accelerated by applying a force of $30 \, N$. The change in the momentum of the body after $2 \, sec$ 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 $N$)

$A$ ping-pong ball of mass $m$ is floating in air by a jet of water emerging out of a nozzle. If the water strikes the ping-pong ball with a speed $v$ and just after collision the water falls dead,the rate of flow (in $kg/s$) of water in the nozzle is equal to

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

$A$ solid horizontal surface is covered with a thin layer of oil. $A$ rectangular block of mass $m = 0.4 \ kg$ is at rest on this surface. An impulse of $1.0 \ N \ s$ is applied to the block at time $t = 0$ so that it starts moving along the $x$-axis with a velocity $v(t) = v_0 e^{-t/\tau}$,where $v_0$ is a constant and $\tau = 4 \ s$. The displacement of the block,in metres,at $t = \tau$ is. . . . . . . Take $e^{-1} = 0.37$.

Two balls each of mass $250 \ g$ moving in opposite directions each with a speed $16 \ m \ s^{-1}$ collide and rebound with the same speeds. The impulse imparted to one ball due to the other is