A particle is executing simple harmonic motion with amplitude A. At a distance ' $x$ ' from the mean position, when the particle is moving towards extreme position it receives a blow in the direction of motion which instantaneously doubles its velocity. The new amplitude of the particle is (Frequency is constant during the motion)

• A

  $A$
• B

  $\sqrt{A^2-x^2}$
• C

  $\sqrt{2 \mathrm{~A}^2-3 \mathrm{x}^2}$
• Correct answer
  D

  $\sqrt{4 A^2-3 x^2}$

Hence, the correct answer is option: 'D'.