(Mass of gun)* (Speed of Gun) = (Mass of Bullet)* (Speed of Bullet)" Please correct me if I am wrong here. It only takes a minute to sign up. Would it divide by 3? This is not in my GCSE syllabus - my physics teacher just likes to set us O Level work, which is full of stuff no longer in our syllabus!!! mass(object 1)*initial velocity (object 1) + mass(object2)*initial velocity (object 2)= Mass (object 1)*final velocity (object 1) + mass (object 2)*final velocity (object 2) The Attempt at a Solution:surprised m (oliver)= 59.1 kg, m(rock)= 0.588 kg, initial velocity = 19.8 m/s p(oliver+ rock)= mv Using ℏ c = 197.33 MeV fm, and m c 2 = E e = 937 MeV. I used (Mass of trolley)*(Speed of trolley) = (Mass of man)*(Speed of man). The question is basically an atom absorbs a photon (energy E), rest mass of atom is m, find recoil velocity in terms of E and m after absorbtion. Answer Using the principle of conservation of Momentum: Momentum Before = Momentum After 0 = M1 x V1 – M2 x V2 M2 x V2 = M1 x V1. What is the best shape for a soccer goal post? You are using an out of date browser. Can anyone explain how they got to this? $$ E_{recoil} = \frac{ {E_\mathrm\gamma}^2}{2Mc^2} $$ This provides me with the correct recoil energy which I then use to get back to velocity. I understand that you feel the problem seems to approximate away the relativistic recoil velocity, but in that case wouldn't the mass also … The best answers are voted up and rise to the top p i = m 1 v i 1. First I thought I would have to convert both masses so they are in the same units, so I converted 4kg to 4000g. " Her mass (including the gun) is 56 kg. MV = MV (mass times velocity equals mass times velocity), the momentum must be equal on both sides of the equation. P b = P a. As I said, it is simple arithmetic and the formula for recoil energy is simply E=1/2 MV Squared, with “M” being mass of the gun and “V” being the recoil velocity. If the gun has a mass of 2kg and the bullet has a mass of 10g (0.01 kg) what speed does the bullet come out at? what are the applications of archimedes principle, Eventhough gravity's value is very less in amount why it is able to hold the whole universe, i want to know the recoil velocity formula for my sum please help me, Offered for classes 6-12, LearnNext is a popular self-learning solution for students who strive for excellence, Sample papers, board papers and exam tips. µ 1+ v0 +v 2c: (12) The recoil shift has been absorbed into the Doppler shift, but the relevant velocity is (v0 + v)=2, that is the mean, or arithmetical average of the velocities before and after the absorption. Problem #3 -Finding Recoil Velocity A gun of mass 4 kg fires a bullet of mass 0.15kg at 250 m/s. (a) Find the recoil velocity of a 70.0-kg ice hockey goalie, originally at rest, who catches a 0.150-kg hockey puck slapped at him at a velocity of 35.0 m/s. Substituting this into the above equation would give a final figure for the recoil energy of 3.15 ft/lb. Can someone please help me solve this problem? (b) How much kinetic energy is lost during the collision? Recoil is the rearward thrust generated when a gun is being discharged. From the above, it can be seen that the weight of the weapon has a very great influence on the recoil energy. Recoil is measured in something called a recoil pendulum, or calculated by mathematical formula based on Newton's physical law that says for every action there is an equal and opposite reaction. The formula for the recoil of a gun is: VG = (VB • Bt)/Gn 32 points Explain recoil velocity and derive formula. Ask your question. Sep 22, 2018. Yay, thank you both for your help - I'm really glad I managed to find some help! The recoil velocity of a cannon is calculated after it launches a projectile. For a better experience, please enable JavaScript in your browser before proceeding. No further mathematical solution is needed for this problem. Physics Secondary School +5 pts. Physics. This speed is small, but it isn't negligible. Initial momentum of the system including the gun and the bullet = 0 Homework Equations i think i need th emomentum of the photon which i believe is p = m(rel) * c and rest mass of atom m = E/c^2 but that is as far as i get. from this i can calculate the velocity of the hydrogen atom. What is the best shape for a soccer goal post? Use mass m and velocity v. 2)Now relate the equation in (1) to atom's momentum p a. a for atom. View Queries. Couldn't quite get my head round the whole theory, just trying to muddle my way through haha! Probably something off the O Level Spec that's not on the syllabus anymore! Hello, I am not sure if this thread is still active but I am doing the same kind of physics problem for homework, and I think I have come to a conclusion from all the helpful stuff on here, but just wondered if someone can check it over for me? I have such a stupid Physics teacher who doesn't actually bother teaching us anything, so I have to learn everything via my textbook, and the internet if that fails! The well-known American author, Bill Bryson, once said: “Physics is really nothing more than a search for ultimate simplicity, but so far all we have is a kind of elegant messiness.” Physics is indeed the most fundamental of the sciences that tries to describe the whole nature with thousands of mathematical formulas. So I substituted in the numbers. $\begingroup$ Also, in equation (2), it seems that the right side includes both the kinetic energy twice. In hand-held small arms, the recoil … It says in my textbook that the total momentum before and after the collision will be the same... Yep, the total momentum before and after will be the same. The rifle, on the other hand, has a mass (mR) of 3,632 grams, since there are 454 grams in a pound. Momentum of bullet = 100kgm/s = momentum of gun = 20*v v = recoil velocity = 100/20 = 5m/s Therefore, the recoil velocity of … I believe I have to use the following somehow: $$ E^2 - (pc)^2 = (mc^2)^2 $$ Any time you understand the motion of a system for which F extermal Δt≈0, you begin with the Conservation of Momentum equation. Hmm, maybe that's more advanced level because my GCSE textbook says nothing at all about energy. :D. Its seems that since that 19.8 m/s is the velocity oliver will continue with, hence that would be the recoil velocity? You are using an out of date browser. Also, can anyone tell me if there is a difference between 'initial speed of recoil' and 'initial speed'? Since it recoils exactly backwards, θ = π, so ( 1 − c o s ( θ) = 1 − c o s ( π) = 2. Ask for details ; Follow Report by Ameyjadhav1234 17.10.2018 Log in to add a comment What do you need to know? Where M1 is the mass of the bullet; V1 is the velocity of the bullet If the initial speed of the man is 4m/s what is the initial speed of the trolley?" the mass of the nucleus). $\begingroup$ I have never seen the term recoil velocity in this context. p = m ⋅ v where m-the hydrogen atom mass, v-its velocity. However, I am not sure how this formula is derived using basic energy formulas. Never heard of that formula. The Attempt at a Solution. Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. The recoil velocity of a gun is a simple application of the conservation of momentum where the moment of the bullet going away is equal to the momentum of the gun recoil. Click here 👆 to get an answer to your question ️ what is recoil velocity and please mention it's formula if it has one. After you input the necessary data such as the bullet weight, bullet velocity, powder charge weight, and the firearm weight it will output the recoil impulse, recoil velocity, and the recoil energy of the firearm. The basketball player’s recoil velocity is 0.048 m/s opposite to the direction at which the ball was shot. Unless, you had meant to type m0? The formula for the recoil of a gun is: VG = (VB • Bt)/Gn . I used the same equation for the questions that wanted initial speed rather than initial speed of recoil but not 100% sure this is correct. :), Ok, well the question was "A man of mass 80kg jumps of a trolley of mass 320kg. So the speed of each truck ends up 6m/s. Are we talking about the lifetime of an electronically excited state here? Ok, thank you - yeah, the topic of the lesson was conservation of momentum, but my teacher was going on about how it doesn't actually exist, and Newton was wrong or something! The man’s average speed is 25 ÷ 6 = 4.2 m/s.So he will not catch a bus moving at 5 m/s. When a bullet is fired from a gun,the gun moves back,opposite to the direction of motion of the bullet.This backward motion of the gun is called recoil and the velocity with it moves back is called recoil velocity.Before firing the bullet,both the bullet and the gun are at rest.Hence,the total momentum is zero.After firing the bullet,the bullet moves forward with a … Realize that Oliver and his rock are originally, also it says that if oliver throws the rock he would throw it at 19.8 m/s, Okay, I'm late by only 2 minutes this time. Use m1*initial velocity1 + m2*initial velocity2= m1*final velocity1+ m2*final velocity2, 2021 © Physics Forums, All Rights Reserved. 3 and then divide the flrst equation by the second to obtain v0 +v 2c¡!0) !0 =! We have to find the recoil velocity of the gun. The recoil velocity of guns or cannons, therefore, depends on the velocity with which the bullet or cannonball is thrown in the forward direction and on the ratio of the mass of bullet/ball with gun/cannon. So, λ f = λ i + 2 π ℏ c m c 2. anvaythegreat2005 anvaythegreat2005 22.12.2018 Physics Secondary School answered What is recoil velocity and please mention it's formula … A gun has a recoil speed of 2 m/s when firing. For a better experience, please enable JavaScript in your browser before proceeding. The recoil velocity is the result of conservation of linear momentum of the system. Motion of box on inclined plane connected by spring to a wall. 2021 © Physics Forums, All Rights Reserved. Consider particles 1 and 2 with masses m 1, m 2, and velocities u 1, u 2 before collision, v 1, v 2 after collision. Aww man, and I was doing so well. JavaScript is disabled. JavaScript is disabled. Hello, I am not sure if this thread is still active but, Hiya. $\endgroup$ – Klaus-Dieter Warzecha Mar 29 '17 at 21:40 If the weight of the weapon is reduced to 1 lb, then the recoil velocity is 20.0 ft/s and the recoil energy is 6.3 ft/lb. To calculate the motion of everyday objects such as toy cars or tennis balls: Motion of box on inclined plane connected by spring to a wall. It may not display this or other websites correctly. P r e c o i l = E γ c, which can be written in terms of the recoil velocity according to, v r e c o i l = E γ (m e + m p) c. In the last expression, m p is the mass of a proton (i.e. The negative sign implies that the direction of recoil velocity is opposite to the direction of the velocity of a bullet or cannonball. All I could decipher from his ramblings was that everything at the start is speed 0. The conservation of the total momentum before and after the collision is expressed by: + = +. That is, the first term is the total energy, and so the second should be unnecessary. Likewise, the conservation of the total kinetic energy is expressed by: + = +. Use this calculator to calculate the recoil on you rifles, handgun, and other firearms. What is the recoil velocity of the gun after? In fact every projection system experiences a recoil velocity whether it is gun, crossbow, bow and arrow, rocket launchers. recoil velocity equation physics. Let us assume a gun of 20 kg shoots a bullet of 1 kg in a velocity of 100m/s. The gun has zero total momentum before firing and afterwards the gun has negative acceleration. The mistake is right there. It may not display this or other websites correctly. In an elastic collision, both momentum and kinetic energy are conserved. v = p m = 6.81 ⋅ 10 − 27 1.67 ⋅ 10 − 27 = 4.078 m s. recoil energy of the hydrogen atom will be. In technical terms, the recoil is a result of conservation of momentum, as according to Newton's third law the force required to accelerate something will evoke an equal but opposite reactional force, which means the forward momentum gained by the projectile and exhaust gases will be mathematically balanced out by an equal and opposite momentum exerted back upon the gun. Recoil Energy Calculator. Erm, no haha! After the bump the speed of the 3 trucks combined will be less than the original speed of the first truck.