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A disc is rotating with angular velocity...

A disc is rotating with angular velocity `omega`. A force F acts at a point whose position vector with respect to the axis of rotation is r. The power associated with torque due to the force is given by

A

`(r xxF). omega`

B

`(r xx F) xx omega`

C

`r xx (F. omega)`

D

`r. (F xx omega)`

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The correct Answer is:
To solve the problem, we need to find the power associated with the torque due to the force acting on a rotating disc. Let's break down the steps to arrive at the solution. ### Step-by-Step Solution: 1. **Understand the System**: - We have a disc rotating with an angular velocity \( \omega \). - A force \( F \) is applied at a point whose position vector with respect to the axis of rotation is \( R \). 2. **Define Torque**: - The torque \( \tau \) due to the force \( F \) acting at point \( R \) is given by the cross product: \[ \tau = R \times F \] 3. **Define Power**: - The power \( P \) associated with the torque is defined as the dot product of the torque vector and the angular velocity vector: \[ P = \tau \cdot \omega \] 4. **Substitute Torque into Power Equation**: - Substitute the expression for torque into the power equation: \[ P = (R \times F) \cdot \omega \] 5. **Final Expression**: - Thus, the power associated with the torque due to the force is: \[ P = R \times F \cdot \omega \] 6. **Identify the Correct Option**: - The correct expression for power \( P \) is \( R \times F \cdot \omega \), which matches with option 1. ### Conclusion: The power associated with the torque due to the force is given by: \[ P = R \times F \cdot \omega \] Thus, the correct answer is option 1.

To solve the problem, we need to find the power associated with the torque due to the force acting on a rotating disc. Let's break down the steps to arrive at the solution. ### Step-by-Step Solution: 1. **Understand the System**: - We have a disc rotating with an angular velocity \( \omega \). - A force \( F \) is applied at a point whose position vector with respect to the axis of rotation is \( R \). ...
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DC PANDEY ENGLISH-ROTATION-Check point 9.2
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  8. A disc is rotating with angular velocity omega. A force F acts at a po...

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  9. Angular momentum is

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  10. The unit mass has r = 8 hat(i) - 4 hat(j) and v = 8 hat(i) + 4 hat(j) ...

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  11. If the earth is a point mass of 6 xx 10^(24) kg revolving around the s...

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  12. A particle with the position vector r has linear momentum p. Which of ...

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  13. By keeping moment of inertia of a body constant, if we double the time...

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  14. It torque is zero, then

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  15. Total angular momentum of a rotating body is conserve, if the net torq...

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  16. The angular momentum of a rotating body changes from A(0) to 4 A(0) in...

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  17. If the radius of earth contracts 1/n of its present day value, the len...

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  18. A thin circular ring of mass M and radius R is rotating about its axis...

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  19. A disc of mass 2 kg and radius 0.2 m is rotating with angular velocity...

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