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NEET2026PhysicsChapterActual

The positions of two particles, A and B, moving along a straight line (x-axis) are given by the equations x_A = 4t^2 + 2t - 5 and x_B = 4t^2 + 2t + 3 , where x is in meters and t is in seconds. Which of the following statements correctly describes the state of particle A with respect to an observer on particle B?

Options

  1. AParticle A is moving towards B with a constant relative velocity of 8 m/s .
  2. BParticle A is accelerating away from B with a relative acceleration of 8 m/s ^2 .
  3. CParticle A is moving with a variable velocity with respect to particle B.
  4. DParticle A is permanently at rest with respect to particle B.

Correct answer

D. Particle A is permanently at rest with respect to particle B.

Step-by-step solution

The position of particle A is given by x_A = 4t^2 + 2t - 5 The position of particle B is given by x_B = 4t^2 + 2t + 3 The relative position of particle A with respect to particle B is: x_ AB = x_A - x_B x_ AB = (4t^2 + 2t - 5) - (4t^2 + 2t + 3) = -8 m The relative velocity of particle A with respect to particle B is: v_ AB = dx_ AB dt = d dt (-8) = 0 m/s Since the relative velocity is zero at all times, particle A is permanently at rest with respect to particle B. Answer: Particle A is permanently at rest with resp

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