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JEE Main20198 Apr 2019Morning ShiftPhysicsCenter of Mass, Momentum and CollisionActual

Four particles A , B , C and D with masses m A = m , m B = 2 m , m C = 3 m  and m D = 4 m are at the corners of a square. They have accelerations of equal magnitude with directions as shown. The acceleration of the centre of mass of the particles is:

Options

  1. Aa 5 i ^ + j ^
  2. Ba 5 i ^ - j ^
  3. Ca i ^ + j ^
  4. DZero

Correct answer

B. a 5 i ^ - j ^

Step-by-step solution

a → A = - a i ^ a → B = a j ^ a → C = a i ^ a → D = - a j ^ a → c m = m a a → a + m b a → b + m c a → c + m d a → d m a + m b + m c + m d a → c m = - m a i ^ + 2 ma j ^ + 3 ma i ^ - 4 ma j ^ 10 m = 2 ma i ^ - 2 ma j ^ 10 , = a 5 i ^ - a 5 j ^ = a 5 i ^ - j ^

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