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NTA Abhyas JEE Main2020PhysicsLaws of MotionPractice

What is the linear velocity if the angular velocity vector is ω → = 3 i ^ − 4 j ^ + k ^ and position vector is r → = 5 i ^ − 6 j ^ + 6 k ^ ?

Options

  1. A6   i ^ + 2   j ^ − 3   k ^
  2. B− 18   i ^ − 13   j ^ + 2   k ^
  3. C18   i ^ + 13   j ^ − 2   k ^
  4. D6   i ^ − 2   j ^ + 8   k ^

Correct answer

B. − 18   i ^ − 13   j ^ + 2   k ^

Step-by-step solution

As we know that v →   =   ω →   ×   r →   =   ( 3   i ^ − 4   j ^ + k ^ )   ×   ( 5   i ^ − 6   j ^ + 6   k ^ ) ∴         w → ×     r → = | i ^ j ^ k ^ 3 − 4 1 5 − 6 6 | or     w → ×     r → =   i ^   ( − 24 + 6 ) + j ^ ( 5 − 18 ) + k ^ ( − 18 + 20 ) = &#

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