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JEE Main202122 Jul 2021Morning ShiftPhysicsLaws of MotionActual

A bullet of 4 g mass is fired from a gun of mass 4 kg . If the bullet moves with the muzzle speed of 50 ms 1 , the impulse imparted to the gun and velocity of recoil of gun are

Options

  1. A0 . 4   kg   m   s - 1 ,   0 . 1   m   s - 1
  2. B0 . 2   kg   m   s - 1 ,   0 . 05   m   s - 1
  3. C0 . 2   kg   m   s - 1 ,   0 . 1   m   s - 1
  4. D0 . 4   kg   m   s - 1 ,   0 . 05   m   s - 1

Correct answer

B. 0 . 2   kg   m   s - 1 ,   0 . 05   m   s - 1

Step-by-step solution

By momentum conservation, 4 × 10 - 3 ( 50 - v ) - 4 v = 0 v = 4 × 10 - 3 × 50 4 + 4 × 10 - 3 ≈ 0 . 05   m   s - 1 Impulse J = m v = 4 × . 05 = 0 . 2   kg   m   s - 1

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