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NEET2020PhysicsRotational MotionActual

Find the torque about the origin when a force of 3 j ^   N acts on a particle whose position vector is 2 k ^   m .

Options

  1. A6 j ^   N   m
  2. B- 6 i ^   N   m
  3. C6 k ^   N   m
  4. D6 i ^   N   m

Correct answer

B. - 6 i ^   N   m

Step-by-step solution

F → = 3 j ^ N , r → = 2 k ^ τ → = r → × F → = 2 k ^ × 3 j ^ = 6 ( k ^ × j ^ ) = 6 ( - i ^ ) τ → = - 6 i ^   N   m

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