Angular Momentum Of a Particle

Angular momentum (L) can be defined as moment of Linear Momentum about a point.

The angular momentum of a particle of mass m moving with velocity v (having a linear momentum p=mv) about a point is defined as

Angular Momentum Of a Particle
Angular Momentum Of a Particle

Let a particle P of mass m rotating about an Axis through O in the x-y plane. Let the particle has linear momentum p which makes θ with its position vector OP=r, now the angular momentum

Angular Momentum Of a Particle
Angular Momentum Of a Particle

The direction of angular momentum vector L is perpendicular to the plane of vector r and vector p in the sense given by right hand rule. Thus in the present case, Vector L points in Z-direction.

Special Case

(I) If θ= 0 or 180, then sinθ= 0, Therefore L= rpsinθ = 0 (minimum)

Hence, the angular momentum is zero, if the line of action of Linear Momentum pass through the point of rotation.

(II) If θ= 90, then sin90= 1, Therefore L= rpsin90= rp (Maximum)

Hence, the angular momentum is maximum.

NCERT Class 11 Physics Book PDF Free Download

Also Read

SL Arora Class 11 Physics Book PDF Free Download

All In One Arihant Class 11 Physics Book PDF Free Download

NCERT Class 11 Physics Hand Written Notes Chapter-Wise
Scroll to Top