Question

A particle of mass m is moving along the line y=b,z=0 with constnat speed v. State whether the angular momentum of particle about origin is increasing. Decreasing or constant.

Answer 1

the angular momentum of a particle of mass m moving along the line y=b;z=0 is constant

The angular momentum of any particle is given by

                           L=r*P

                             =IrI IpI sinФ

                  here r is the radius of the vector from origin

                           p is the angular momentum                                          

                           r sinФ is the horizontal component of radius vector i.e

                           r sinФ=b  which is constant at any given point

                         hence p is constant and r is constant

                                   so angular momentum remains constant about origin

Answer 2

Answer:

Remains Constant

Explanation:

|L|=mvrsinθ=mvr⊥=mvb

∴|L|= constant as m, v and b all are constant.

The direction of r×v also remains the same. Therefore, the angular momentum of particles about origin remains constant with due course of time.