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Angular momentum
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What is angular momentum? Angular
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momentum is the quantity of rotational
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motion possessed by a rotating object
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which depends on its moment of inertia
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and angular velocity. Angular momentum
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describes how much rotation an object
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has and how difficult [clears throat] it
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is to stop its rotation. It is a vector
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quantity, meaning it has both magnitude
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and direction. In a system where no
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external torque acts, angular momentum
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is conserved. This means the total
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angular momentum remains constant.
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Angular momentum depends on how mass is
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distributed relative to the axis of
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rotation and how fast the object is
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rotating. Imagine a figure skater
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spinning with arms stretched out. When
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the skater pulls the arms inward, they
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spin faster. This happens because
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angular momentum is conserved. Examples:
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a spinning wheel, Earth rotating about
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its axis, a rotating disk, a figure
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skater spinning faster by pulling in
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arms, motion of planets around the Sun.