A body of mass $10 kg$ is projected at an angle of $45^{\circ}$ with the horizontal. The trajectory of the body is observed to pass through a point $(20,10)$. If $T$ is the time of flight, then its momentum vector, at time $t =\frac{ T }{\sqrt{2}}$, is.
$\left[\right.$ Take $\left.g=10 m / s ^{2}\right]$
$100 \hat{ i }+(100 \sqrt{2}-200) \hat{ j }$
$100 \sqrt{2} \hat{i}+(100-200 \sqrt{2}) \hat{j}$
$100 \hat{ i }+(100-200 \sqrt{2}) \hat{ j }$
$100 \sqrt{2} \hat{i}+(100 \sqrt{2}-200) \hat{j}$
Two billiard balls of equal mass $30 \,{g}$ strike a rigid wall with same speed of $108\, {kmph}$ (as shown) but at different angles. If the balls get reflected with the same speed then the ratio of the magnitude of impulses imparted to ball $'a'$ and ball $'b'$ by the wall along $'X'$ direction is :
A trolley containing water has total mass $4000\, kg$ and is moving at a speed of $40\, m/s$. Now water start coming out of a hole at the bottom of the trolley at the rate of $8\,kg/s$. Speed of trolley after $50\, s$ is ............ $m/s$
A body of mass $3\,kg$ is acted on by a force which varies as shown in the graph below. The momentum acquired is given by ........... $N-s$
The magnitude of force acting on a particle moving along $x$-axis varies with time $(t)$ as shown in figure. If at $t=0$ the velocity of particle is $v_0$, then its velocity at $t=T_0$ will be
A body, whose momentum is constant, must have constant