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JEE Main20206 Sep 2020Evening ShiftPhysicsMotion in One DimensionActual

A particle moving in the xy -plane experiences a velocity dependent force F → = k υ y i ^ + υ x j ^ , where υ x and υ y are the x and y components of its velocity υ → . If a → is the acceleration of the particle, then which of the following statements is true for the particle ?

Options

  1. Aquantity υ → × a → is constant in time
  2. BF → arises due to a magnetic field
  3. Ckinetic energy of particle is constant in time
  4. Dquantity υ → . a → is constant in time

Correct answer

A. quantity υ → × a → is constant in time

Step-by-step solution

F → = k v → ⇒ F → ‖ v → ⇒ a → ‖ v → ⇒ v → × a → = 0 always

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