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NEETPhysicsMotion in One Dimension

Assertion : A body of mass 4 kg has an initial velocity (5 i ~m / s ). It is subjected to a force of (4 j ~N ). The displacement of the body from the origin after 4 s will be 21.5 m. Reason : The equation ( v = u + a t ) can be applied to obtain ( v ), if ( a ) is constant.

Options

  1. AIf both Assertion and Reason are correct and Reason is the correct explanation of Assertion
  2. BIf both Assertion and Reason are correct but Reason is not the correct explanation of Assertion
  3. CIf Assertion is true but Reason is false
  4. DIf Assertion is false but Reason is true

Correct answer

B. If both Assertion and Reason are correct but Reason is not the correct explanation of Assertion

Step-by-step solution

- Assertion: For a particle moving along a straight line, if the velocity is zero at an instant, the acceleration may or may not be zero at that instant. (Correct. e.g., a ball thrown upwards at its peak, ( v =0 ) but ( a = g ). Or a body moving with constant velocity, ( v =0, a =0 )). - Reason: Acceleration is the rate of change of velocity. (Correct definition). - The reason correctly defines acceleration but does not explain why acceleration may not be zero when velocity is zero at an instant. - Assertion: For a

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