angular momentum

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angular momentum

MRI
The cross product of the ordinary momentum of a particle and its position vector, running from the axis of rotation to the body whose momentum is being determined.

In absence of external forces, the angular momentum (AM) remains constant; therefore, a rotating body tends to maintain the same axis of rotation. When torque is applied to a rotating body, the resulting change in AM results in precession. Momentum involved in the rotation of a body about an axis is conserved, as is ordinary momentum. Atomic nuclei possess an intrinsic AM known as “spin”, which is measured in multiples of Planck’s constant.

an·gu·lar mo·men·tum

(ang'gyŭ-lăr mō-men'tŭm)
The spin of MR active nuclei, which depends on the balance between the number of protons and neutrons in the nucleus.
References in periodicals archive ?
Thanks to Earth's rotational momentum, the sky, however, spins completely around the north and south celestial poles every 24 hours or so without relying on fluid mechanics to keep its heavenly wheel turning.