Question

A particle having mass 5 kg is moving on a straight line y = 2x + 4 with velocity $3\sqrt{5}$ m/s. Find its angular momentum about origin.

Answer 1

Mass of the particles$=5kg$

Velocity of the particle$=3\sqrt{5}m/s$

Equation of motion of particle $y=2x+4$

Angular momentum of the particle about the origin, $L=r\times p=mvr\sin \theta$

where

$r=$ Perpendicular distance between the line and origin

$\sin \theta =1$

For r put x=0

$r=y=4$

Angular momentum of the particle about the origin $=mvr=5\times 3\sqrt{5}\times 4$

$=134.16kg.m^2/s$