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NTA Abhyas JEE Main2020PhysicsCenter of Mass, Momentum and CollisionPractice

A shell in air explodes into n equal fragments, k of the fragments reach the ground earlier than the other fragments. The acceleration of their centre of mass subsequently will be

Options

  1. Ag
  2. Bn - k g
  3. Cn - k g k
  4. Dn - k n g

Correct answer

D. n - k n g

Step-by-step solution

a c m = Σ m i a i Σ m i Till all the particle remains in air center of mass remains stationary. When k particles hit the ground then center of mass shifts with accelaration : a c m = n - k n g

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