Question

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

• A. zero
• B. 60 units
• C. 7.5 units
• D. 40 units

Answer 1

Answer: (B)

The angular momentum,
$L=mvb\cos \theta$
where, $m=$ mass of particle
$V=$ velocity of particle
$b=$ position of particle with respect to origin and $\theta$
= angle between momentum vector and position vector.
$=5\times 3\sqrt{2}\times 4\times \cos 45^{\circ }$
$L=60$ units