angular momentum(redirected from Angular impulse)
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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.