Class 11 Exam  >  Class 11 Questions  >  A machine gun has a mass of 20 kg fires 35 g ... Start Learning for Free
A machine gun has a mass of 20 kg fires 35 g bullets at the rate of 400 bullets per second with a speed of 400ms-1 .What force must be applied to the gun to keep in the position?
  • a)
    5800 N
  • b)
    5600 N
  • c)
    560 N
  • d)
    56 N
Correct answer is option 'B'. Can you explain this answer?
Verified Answer
A machine gun has a mass of 20 kg fires 35 g bullets at the rate of 40...
To conserve the momentum each time a single bullet is fired,
the reverse speed gained by the gun from one bullet is 
V = 400 X .035 / 20
= 0.7 m/s
Thus total speed gained in a second is = 0.7 X 400 = 280 m/s
As total speed is gained in one second only the acceleration produced = 280 m/s2
Thus total force applied on the gun by the bullets = 20 x 280 
= 5600 N
View all questions of this test
Most Upvoted Answer
A machine gun has a mass of 20 kg fires 35 g bullets at the rate of 40...
Given:
Mass of the machine gun, m = 20 kg
Mass of each bullet, m_b = 35 g = 0.035 kg
Rate of firing, n = 400 bullets/second
Speed of each bullet, v = 400 m/s

To find: Force required to keep the gun in position

Formula used:
Force = rate of change of momentum

Calculation:
1. Mass of each bullet, m_b = 0.035 kg
2. Total mass of n bullets fired in 1 second =
Mass of one bullet x number of bullets fired in 1 second
= m_b x n
= 0.035 x 400
= 14 kg
3. Initial momentum of the bullets, p_i =
Total mass of n bullets fired in 1 second x velocity of each bullet
= 14 x 400
= 5600 kg m/s
4. Final momentum of the bullets, p_f = 0 (since the bullets stop after firing)
5. Change in momentum, Δp = p_f - p_i = - p_i = -5600 kg m/s
6. Rate of change of momentum, Δp/Δt = -5600 kg m/s
7. Force required to keep the gun in position, F =
Rate of change of momentum x mass of the gun
= -5600 x 20
= -112000 N
(Note that the negative sign indicates that the force is acting in the opposite direction to the motion of the bullets)

Therefore, the force required to keep the gun in position is 5600 N (option B).
Free Test
Community Answer
A machine gun has a mass of 20 kg fires 35 g bullets at the rate of 40...
We can also apply this formula F=mnv m=mass of bullent in kg n=no. of bullet per second v=velocity of bullet in m/s F=0.035×400×400 F=5600N
Attention Class 11 Students!
To make sure you are not studying endlessly, EduRev has designed Class 11 study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Class 11.
Explore Courses for Class 11 exam

Similar Class 11 Doubts

Top Courses for Class 11

A machine gun has a mass of 20 kg fires 35 g bullets at the rate of 400 bullets per second with a speed of 400ms-1 .What force must be applied to the gun to keep in the position?a)5800 Nb)5600 Nc)560 Nd)56 NCorrect answer is option 'B'. Can you explain this answer?
Question Description
A machine gun has a mass of 20 kg fires 35 g bullets at the rate of 400 bullets per second with a speed of 400ms-1 .What force must be applied to the gun to keep in the position?a)5800 Nb)5600 Nc)560 Nd)56 NCorrect answer is option 'B'. Can you explain this answer? for Class 11 2024 is part of Class 11 preparation. The Question and answers have been prepared according to the Class 11 exam syllabus. Information about A machine gun has a mass of 20 kg fires 35 g bullets at the rate of 400 bullets per second with a speed of 400ms-1 .What force must be applied to the gun to keep in the position?a)5800 Nb)5600 Nc)560 Nd)56 NCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for Class 11 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A machine gun has a mass of 20 kg fires 35 g bullets at the rate of 400 bullets per second with a speed of 400ms-1 .What force must be applied to the gun to keep in the position?a)5800 Nb)5600 Nc)560 Nd)56 NCorrect answer is option 'B'. Can you explain this answer?.
Solutions for A machine gun has a mass of 20 kg fires 35 g bullets at the rate of 400 bullets per second with a speed of 400ms-1 .What force must be applied to the gun to keep in the position?a)5800 Nb)5600 Nc)560 Nd)56 NCorrect answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for Class 11. Download more important topics, notes, lectures and mock test series for Class 11 Exam by signing up for free.
Here you can find the meaning of A machine gun has a mass of 20 kg fires 35 g bullets at the rate of 400 bullets per second with a speed of 400ms-1 .What force must be applied to the gun to keep in the position?a)5800 Nb)5600 Nc)560 Nd)56 NCorrect answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of A machine gun has a mass of 20 kg fires 35 g bullets at the rate of 400 bullets per second with a speed of 400ms-1 .What force must be applied to the gun to keep in the position?a)5800 Nb)5600 Nc)560 Nd)56 NCorrect answer is option 'B'. Can you explain this answer?, a detailed solution for A machine gun has a mass of 20 kg fires 35 g bullets at the rate of 400 bullets per second with a speed of 400ms-1 .What force must be applied to the gun to keep in the position?a)5800 Nb)5600 Nc)560 Nd)56 NCorrect answer is option 'B'. Can you explain this answer? has been provided alongside types of A machine gun has a mass of 20 kg fires 35 g bullets at the rate of 400 bullets per second with a speed of 400ms-1 .What force must be applied to the gun to keep in the position?a)5800 Nb)5600 Nc)560 Nd)56 NCorrect answer is option 'B'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice A machine gun has a mass of 20 kg fires 35 g bullets at the rate of 400 bullets per second with a speed of 400ms-1 .What force must be applied to the gun to keep in the position?a)5800 Nb)5600 Nc)560 Nd)56 NCorrect answer is option 'B'. Can you explain this answer? tests, examples and also practice Class 11 tests.
Explore Courses for Class 11 exam

Top Courses for Class 11

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev