Show thath and angular momentum have the same units.

Short Answer

Expert verified

The unit for angular momentum isJ . SinceN is a dimensionless quantity, both angular momentum andh have same units. Thus, the units ofh is J·s.

Step by step solution

01

Definition of Angular Momentum

Angular momentum, property characterizing the rotary inertia of an object or system of objects in motion about an axis that may or may not pass through the object or system.

02

Show that h and angular momentum have the same units.

Bohr postulated that the angular momentum of electrons in a hydrogen atom is quantized. The translation angular momentum of the electron is an integral multiple ofh.

Mathematically angular momentum can be expressed as

L=Nh.....(1)

Hereh is12π times the Planck constanthand Nis the integer.

The angular momentum of a particle of massmmoving in circular orbit of radiusr with velocityvis given by

L=mvr.....(2)

Here mass is measured in kg, velocity is measured inm/sand radius is measured in meters.

03

Explanation

The units for angular momentum is

L=kgm/sm=kg·m2/sss=kg·m2/s2·s

As is equivalent to JoulesJ, the unit for angular momentum is J. Since Nis a dimensionless quantity, both angular momentum and hhave same units. Thus, the units ofh is J·s.

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