The diameter of a flywheel is $1 \,m$. It has a mass of $20 \,kg$. It is rotating about its axis with a speed of $120$ rotations in one minute. Its angular momentum in $kg-m^2/s$ is (in $4$)

$A$ particle of mass $m$ moves along a straight line $AB$ in the $XY$ plane. Let $L_A$ and $L_B$ be the angular momentum of the particle about the origin $O$ when it is at points $A$ and $B$ respectively. Then:

$A$ particle moves in a circular path with decreasing speed. Choose the correct statement.

$A$ uniform rod of mass $m$ and length $l$ is moving with velocity $u$ in a direction perpendicular to its length. $A$ blow of impulse $J$ is applied in the direction of $u$,perpendicular to its length at a distance $l/4$ from its center at point $P$,such that the instantaneous velocity of point $P$ is $2u$. Then the velocity of its center of mass will be:

$A$ particle of mass $m = 5$ is moving with a uniform speed $v = 3\sqrt{2}$ in the $XOY$ plane along the line $Y = X + 4$. The magnitude of the angular momentum of the particle about the origin is .......

An angular impulse of $20 \,Nms$ is applied to a hollow cylinder of mass $2 \,kg$ and radius $20 \,cm$. The change in its angular speed is ............. $rad/s$.