Question

A particle of mass $m=5$ units is moving with uniform speed $v=3 \sqrt{2}$ units in the $X Y$ -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