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Most Important Selected Qs for JEE AdvancedPhysicsCenter of Mass, Momentum and Collision

Paragraph: According to the principle of conservation of linear momentum if the external force acting on the system is zero, the linear momentum of the system will remain conserved. It means if the centre of mass of a system is initially at rest, it will remain at rest in the absence of external force, that is the displacement of centre of mass will be zero. A plank of mass M is placed on a smooth horizontal surface.

Options

  1. AKm ( M + m )
  2. Bm ( M + m )
  3. CK m M(M+m)
  4. DKm ( M + m )

Correct answer

C. K m M(M+m)

Step-by-step solution

Mv _ M - mv _ m =0 ....(i) 1 2 ~K t^2= 1 2 Mv _ M ^2+ 1 2 mv _ m ^2 ....(ii) Solving (i) and (ii) v _ M = Km M ( M + m )

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