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प्रश्न
State the law of conservation of angular momentum and explain with a suitable example.
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उत्तर
Statement: The angular momentum of a body remains constant if the resultant external torque acting on the body is zero.
Example:
- A ballet dancer makes use of the law of conservation of angular momentum to vary her angular speed.
- The torque acting on her body is zero. By the law of conservation of angular momentum, L = constant
Iω = constant ⇒ ω ∝1/I - When she suddenly folds her arms and brings the stretched leg close to the body, her angular velocity increases on account of the decrease in moment of inertia. This helps in rotating safely on her legs.
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संबंधित प्रश्न
Obtain an expression for torque acting on a body rotating with uniform angular acceleration.
Define moment of inertia. State its SI unit and dimensions.
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mass is whirled in a circular path with constant angular velocity and its linear velocity is v. If the string is now halved keeping the angular momentum same, the linear velocity is ______.
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Calculate the change in angular momentum of the electron when it jumps from third orbit to first orbit in hydrogen atom.
(Take h = 6.33 × 10−34 Js)
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(Velocity of sound in air = 300 m/s)
