A body of mass 5kg moving with a uniform speed 3 2 m s ^ - 1 in X -...

Equation of line given: $y - x - 4 = 0$.

Let ${d}_{1}$ be the perpendicular distance of given line from origin.

${d}_{1} = \left|\dfrac{- 4}{\sqrt{{1}^{2} + {1}^{2}}}\right| = 2\sqrt{2}$

So, $| \overset{\to}{L} | = mv{d}_{1} = 5 \times 3\sqrt{2} \times 2\sqrt{2}kg{m}^{2}{s}^{- 1}$

$= 60kg{m}^{2}{s}^{- 1}$