Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 202122 JulyMorning Shift
Exam
JEE Main
Year
2021
Date
22 July
Shift
Morning Shift
Subject
Physics
Chapter
Laws of Motion

JEE Main 2021 · 22 July · Morning Shift · Physics · Laws of Motion

A bullet of 4g mass is fired from a gun of mass 4kg . If the bullet...

A bullet of 4g4g mass is fired from a gun of mass 4kg.4kg . If the bullet moves with the muzzle speed of 50ms1,50{ms}^{1}, the impulse imparted to the gun and velocity of recoil of gun areA bullet of 4g mass is fired from a gun of mass 4kg . If the bullet moves with the muzzle speed of 50 ms ^ 1 , the

Options

  1. A0.4kgms−1,0.1ms−10 . 4kg{ms}^{- 1}, 0 . 1{ms}^{- 1}
  2. B0.2kgms−1,0.05ms−10 . 2kg{ms}^{- 1}, 0 . 05{ms}^{- 1}
  3. C0.2kgms−1,0.1ms−10 . 2kg{ms}^{- 1}, 0 . 1{ms}^{- 1}
  4. D0.4kgms−1,0.05ms−10 . 4kg{ms}^{- 1}, 0 . 05{ms}^{- 1}

Correct answer

B. 0.2kgms−1,0.05ms−10 . 2kg{ms}^{- 1}, 0 . 05{ms}^{- 1}

Step-by-step solution

A bullet of 4g mass is fired from a gun of mass 4kg . If the bullet moves with the muzzle speed of 50 ms ^ 1 , the

By momentum conservation,
4×10−3(50−v)−4v=04 \times {10}^{- 3} ( 50 - v ) - 4v = 0
v=4×10−3×504+4×10−3≈0.05ms−1v = \dfrac{4 \times {10}^{- 3} \times 50}{4 + 4 \times {10}^{- 3}} \approx 0 . 05{ms}^{- 1}
Impulse J=mv=4×.05=0.2kgms−1J = mv = 4 \times . 05 = 0 . 2kgm{s}^{- 1}

Practice Laws of Motion on Quantrex Academy →

More from Laws of Motion

A block takes t time to slide down a plane inclined at 45° to the horizontal. If the… JEE Main 2026Two blocks ( P and Q ) with respectively masses 2 kg and 1.5 kg are joined by a massless… JEE Main 2026A mass of 1 kg is kept on an inclined plane with 30° inclination with respect to… JEE Main 2026Three masses m_1 = 4 kg, m_2 = 4 kg and m_3 = 6 kg are suspended from a fixed smooth… JEE Main 2026A wedge Y with mass of 10 kg and all frictionless surfaces and the inclined surface… JEE Main 2026At t=0 , a body of mass 100 g starts moving under the influence of a force (5 i +10 j )… JEE Main 2026The time taken by a block of mass m to slide down from the highest point to the lowest… JEE Main 2026A 0.5 kg mass is in contact against the inner wall of a cylindrical drum of radius 4 m… JEE Main 2026 Full Laws of Motion list All JEE Main PYQs