A machine gun fires 20 bullets per second, each of mass 40 g at 400 m s -1 . The force needed to hold the gun steady is:

⚛️ Physics · Laws of Motion · NEET & JEE

A machine gun fires 20 bullets per second, each of mass 40 g at 400 m s<sup>-1</sup>. The force needed to hold the gun steady is:

Answer: 320 N.

A 160 N
B 320 N
C 400 N
D 240 N

Correct answer: B. 320 N

Explanation: Force = rate of change of momentum = n m v = 20 × 0.04 × 400 = 320 N.

Free-body diagram of a block on an incline: weight (mg) resolves into mg sinθ along the slope and mg cosθ into the slope, balanced by the normal force N and friction f.

Concept context

Newton's three laws, friction, circular motion, and free body diagrams.

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A machine gun fires 20 bullets per second, each of mass 40 g at 400 m s<sup>-1</sup>. The force needed to hold the gun steady is:

Concept context

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