Bullet Definition and 650 Threads

A bullet is a kinetic projectile, a component of firearm ammunition that is shot from a gun barrel. The term is from Middle French, originating as the diminutive of the word boulle (boullet), which means "small ball". Bullets are made of a variety of materials, such as copper, lead, steel, polymer, rubber and even wax. Bullets are made in various shapes and constructions (depending on the intended applications), including specialized functions such as hunting, target shooting, training and combat. bullets are often tapered, making them more aerodynamic. Bullet sizes are expressed by their weights and diameters (referred to as "calibers") in both imperial and metric measurement systems. For example: 55 grain .223 caliber bullets are of the same weight and caliber as 3.56 gram 5.56mm caliber bullets. Bullets do not normally contain explosives (see Incendiary ammunition and Exploding bullet), but strike or damage the intended target by transferring kinetic energy upon impact and penetration (see terminal ballistics).
Bullets are available singly (as in muzzle-loading and cap and ball firearms), but are more often packaged with propellant as cartridges ("rounds" of ammunition). Bullets are components of paper cartridges, or (much more commonly) in the form of metallic cartridges. Although the word bullet is often used in colloquial language to refer to a cartridge round, a bullet is not a cartridge but rather a component of one. A cartridge is a combination package of the bullet (i.e., the projectile), the case (which holds everything together), the propellant (which provides the majority of the energy to launch the projectile) and the primer (which ignites the propellant). This use of the term bullet (when intending to describe a cartridge) often leads to confusion when a cartridge, and all its components, are specifically referred to. The cartridges, in turn, may be held in a magazine or a belt (for rapid-fire weapons).
The bullets used in many cartridges are fired at muzzle velocities faster than the speed of sound—about 343 metres per second (1,130 ft/s) in dry air at 20 °C (68 °F)—and thus can travel a substantial distance to a target before a nearby observer hears the sound of the shot. The sound of gunfire (i.e. the "muzzle report") is often accompanied with a loud bullwhip-like crack as the supersonic bullet pierces through the air creating a sonic boom. Bullet speeds at various stages of flight depend on intrinsic factors such as sectional density, aerodynamic profile and ballistic coefficient, and extrinsic factors such as barometric pressure, humidity, air temperature and wind speed. Subsonic cartridges fire bullets slower than the speed of sound, so there are no sonic booms. This means that a subsonic cartridge, such as .45 ACP, can be substantially quieter than a supersonic cartridge, such as the .223 Remington, even without the use of a suppressor.Bullets shot by firearms can be used for target practice or to injure or kill animals, or people. Death can be by blood loss or damage to vital organs, or even asphyxiation if blood enters the lungs. Bullets are not the only projectiles shot from firearm-like equipment: BBs are shot from BB guns, airsoft pellets are shot by airsoft guns, paintballs are shot by paintball markers, and small rocks can be hurtled from slingshots. There are also flare guns, potato guns (and spud guns), rubber bullets, tasers, bean bag rounds, grenade launchers, flash bangs, tear gas, RPGs, and missile launchers.

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  1. rcgldr

    Astronaut shoots a bullet into the sun - gravity assists?

    This question came up at another forum. The delta-v of potential guns is limited to the range 3 km/s to 11 km/s (hydrogen gun). Assume the astronaut is either on the moon or orbiting the moon. I'm wondering if a single impulse followed by gravity assists (and ideal planet alignment) could result...
  2. G

    What is the Velocity of the Ball After Impact?

    Homework Statement Instead of using a ballistic pendulum, a bullet with velocity u is fired at a stationary solid ball resting on a surface. If the bullet deflects at an angle of 30◦ to its original path and the ball is nine times more massive than the bullet, what is the velocity of the ball...
  3. L

    Finding a bullet's velocity over time

    Hi, I engage in physics as a hobby, and I'm not extremely familiar with things reaching into calculus levels of math. That said, how would I find the velocity of a bullet at a given time or distance, taking wind/humidity/etc. out of the equation? I know the muzzle velocity only applies to the...
  4. G

    Angle of Displacement of Rod Hit by Bullet in Time

    Homework Statement A rod of mass M y length L can spin freely around a fixed point P, as shown in the picture. A bullet of mass m is shot perpendicular to the rod, and after impact, it is embedded into it. After impact the system realizes small oscillations, and that immediately after impact...
  5. C

    Shooting a bullet at an angle from a given height

    Homework Statement A sniper standing on a 70 meter-tall tower fires his rifle at 30 degrees upwards with the initial velocity of 1000 m/s. What is the range of the bullet and how much time will pass before it hits the ground? Assume no air-resistance. 2. The attempt at a solution I divided...
  6. D

    Newton's law of equal/opposite reaction, and bullet impact...

    When fired, a slug's acceleration down a barrel produces an equal backward force. I get that. What I DON'T get, is why there is no rebounding force counter to a slug's impact by the material being struck? The material/molecules simply get impacted and pushed via the force generated. Why is there...
  7. aatari

    Projectile Problem - Bullet from Raised ground

    Hi Guys, could someone kindly look at my solutions and let me know if I did everything correctly. Thanks a lot! 1. Homework Statement A sniper fires a bullet at 120 m/s at 30° above the horizontal from the roof top of a 35 m high parking garage. If the bullet strikes the level ground beside...
  8. O

    Is it possible to stop a bullet by just using a magnet?

    Stop it or deflect it? and what are the laws and the effects that I need to know to determine something like this?
  9. E

    Is My Physics Calculation on Bullet and Block Interaction Correct?

    Can someone check if I'm doing this problem correctly? Please tell me if I did anything wrong. 1. Homework Statement A 12 g bullet passes horizontally through a 15 cm tall, 20 cm long .5 kg block which is initially at rest on a 1 meter tall table’s edge. The bullet is initially moving 230 m s...
  10. V

    What was the initial temperature of the lead bullet before it melted completely?

    Homework Statement A lead bullet flies at a speed of 450 m / s and, striking a wall perpendicularly, melts completely. What was the bullet temperature before the blow, if for melting it consumes only half of its mechanical energy? Latent melting heat and the specific and melting temperature of...
  11. V

    Thermodynamics, bullet melting ice problem

    Homework Statement An ice cube at the melting temperature that has a mass of 20 g, is struck by a bullet with a mass of 9 g, flying at a certain speed. Determine the speed of the bullet, if it is known that one third of his energy was consumed to break the ice, and the remainder to melt it...
  12. S

    Can a bullet hit someone while free falling?

    If two people are free falling from the sky at the same (high) speed, at the same altitude, but about 20 meters away from each other, and one of them has a gun and tries to shot the other, do they aim directly at the other person so they get a hit (because the bullet would also be falling), or...
  13. donaldparida

    Bullet trajectory: Aiming a gun

    Homework Statement : [/B]A person aims a gun at a bird from a point at a horizontal distance of 100m. If the gun can impart a speed of 500m/s to the bullet , then above what height of the bird he should aim his gun to hit it ? Homework Equations : [/B] H_{max}=\frac{u^2\sin^2\theta}{2g}...
  14. ActuatorA

    Water speed and bullet penetration

    This may be an odd question but I am wondering if water speed affects a bullet's ability to penetrate water. Pardon my lack of knowledge, but I am aware that low caliber bullets can penetrate water past 3ft (Thank you Mythbusters). However, the tests they completed were all based around a pool...
  15. T

    What is the impact of different powder burn rates on rifle bullet pressure?

    I'm trying to understand som basic rifle bullet physics regarding pressure inside the gun barrel. For no particular reason I'm comparing the .308 and 30-06 cartridge. When reading specs on the two I get confused. They both have maximum pressure levels around 415 MPa, but how can that be when the...
  16. Deadawake

    How Does Friction Affect Spring Compression in a Bullet Collision?

    Hi, Please see the attach picture. I solved 3 quetions regarding this problem and I struggle with the 4th one. What I found was that the initial velocity after the collision is 1.98 m/s (Edit: 0.2m/s), and the maximum compression of the spring with no friction beneath is 0.44m (Edit: 0.044m) (I...
  17. D

    Thermodynamics of a cannon ball / musket ball shot bullet

    I am a computer scientist currently writing a 3D simulation for high speed projectiles both sub and supersonic for various shapes and sizes of projectiles. For now I am focused on completing simulation of a simple model of a round ball shaped projectile (ie a cannonball or musket shot). I like...
  18. D

    What formulas should I use to calculate drag for a supersonic bullet?

    I'm a computer scientist currently developing projectile simulators. My software will factor in drag coefficients of various shaped projectiles as well as gravity, air pressures, air density and temperatures at various heights. I am familiar with the drag formula but it's only useful up to Mach...
  19. D

    Drag formula used to calculate bullet hole depth?

    I'm writing a real time 3D physics simulator that simulate bullet ballistics. Can I use the air drag formula that factors in drag coeficient and outputs drag force to calculate how deep a bullet will penetrate a target material? Say I substitute air pressure with target material density. And...
  20. D

    Rotating bullet vs non rotating bullet

    I'm writing a program to simulate bullet impact on various materials. I need to know, will the angular momentum of a spinning bullet give it more impact force? I would assume that if so it would also mean that spinning bullets overcome more air friction if I am supposed to add the angular...
  21. kinalee8

    Velocity of bullet before hitting a pendulum

    <Mentor's note: moved from a technical forum and thus no template.> A pendulum consists of a bob of mass M and a rigid rod of length ℓ with negligible mass. The bob is struck by a bullet of mass m. The bullet passes through the bob and emerges with a speed half that of impact. The shot causes...
  22. R

    How Do You Calculate the Final Speed of a Bullet-Block System?

    Homework Statement A bullet flying horizontally hits a wooden block that is initially at rest on a frictionless, horizontal surface. The bullet gets stuck in the block, and the bullet-block system has a final speed of V_f. Find the final speed of the bullet-block system in terms of the mass of...
  23. Hilmy atha

    How much energy does the force of gravity apply to a bullet?

    Homework Statement A bullet was shot at 40m/s Elevation angle : 37° Bullet mass = 0.01 Kg Question : how much work is done by the force of gravity to the bullet since it was shot until it reaches the ground again Homework Equations mgh = E.Pot 1/2mv ^2 = E kinetic The Attempt at a Solution...
  24. S

    Calculating Force and Impulse of a Bullet Hitting a Man

    Homework Statement A bullet of mass 0.011 kg is fired at a speed of 850 m/s. It embeds itself in a man of mass 90 kg. a) Find the momentum of the bullet before it strikes the man. b) Assuming it takes 0.1 seconds for the bullet to come to rest after hitting the man, calculate the average...
  25. K

    I Bullet clusters & CMB accoustic peaks dark matter

    is it possible the dark matter in bullet clusters & CMB accoustic peaks were the result of black holes, originally from baryonic matter, but galaxy rotation curves are MOND. So MOND + dark matter as black holes from baryon, not dark matter particles
  26. O

    Angular momentum of a bullet problem

    Homework Statement A 4 g bullet traveling at 500 m/s strikes a disk of mass 1 kg and radius 10 cm that is free to rotate around an axis passing through its center. The bullet’s incoming path is 5 cm above the rotation axis and the bullet comes to rest in the position shown in the figure. At how...
  27. J

    MCAT Collisions of a wooden block and bullet

    Hi guys, I'm currently going over Berkerley Review Physics example problem and got confused on a question: Ex. 4.1a : A sharpshooter fires a gun at a wooden block of mass M. If the bullet, of mass (m), becomes lodged inside the block, then which of the following is NOT true? The answer was...
  28. H

    What is the force imparted by the bullet on the block

    Homework Statement A bullet with a mass of 0.045 kg is shot at 560m/s fwd, and it gets dislodged in a stationary block that is 0.5kg. The collision lasts 0.35 seconds. What is the force imparted by the bullet on the block? Homework Equations F=(m(vf-vi))/t The Attempt at a Solution...
  29. M

    Bullet Velocity: 100,000 HP-Powered Distance in 1 Sec

    Hi, Imagine there is a four gram bullet, but someone want to accelerate it with force or power equal to 100,000 horsepower. How far the distance will the lightweight bullet cover in a second?
  30. E

    A bullet pushing a knot out of a wood block

    Homework Statement You shoot a 0.0050-kg bullet into a 2.0-kg wooden block at rest on a horizontal surface (Figure 1) . After hitting dead center on a hard knot that runs through the block horizontally, the bullet pushes out the knot. It takes the bullet 1.0 ms to travel through the block, and...
  31. Wanna_be_Feynman

    Distance a bullet will travel while shot underwater

    Homework Statement hey I am trying to work out the problem: If I shoot an ak47 underwater with 7.62x39mm ammunition, how far will the bullet travel before coming to a stop? Homework Equations The equation that I have used to find the drag force is the drag equation: F =1/2 p*A*C_d*v^2...
  32. Pao44445

    Bullet Momentum Force: 3.15x104 N

    Homework Statement a bullet 15 g travels 300 m/s then hit the plastic sheet that is thick 2 cm and pass through it. After the crash, the bullet travels 90 m/s ( continue to lose the velocity ) How much the average force acting on the bullet? Homework Equations Momentum = Mass x Velocity The...
  33. S

    Mounting of accelerometer on bullet - Drop test

    Hi guys, I am performing drop-weight impact tests on concrete slab. I have designed a bullet made of high tensile steel and I am interested to recorded the acceleration, then convert it to impact force. For this purpose, I need to implement an accelerometer on the bullet. I have tried two...
  34. Kloud

    Spring compression after bullet passes through block

    Homework Statement Its in the screenshot i took. I need someone to walk me through the process of solving this problem because I do not understand how to get the maximum compression distance x of the spring. I know that the momentum of the billet will= the momentum of the block. Homework...
  35. Erenjaeger

    Ice melted by impact of lead bullet

    Homework Statement A 3.20 g lead bullet at 28.0°C is fired at a speed of 210 m/s into a large block of ice at 0°C, in which it becomes embedded. What mass of ice melts (g)? Homework Equations I thought that the KE of the bullet would be transferred into heatThe Attempt at a Solution I used...
  36. C

    Finding velocity and momentum of a bullet and recoiling gun

    Homework Statement A bullet leaves the barrel of a gun with a kinetic energy of 90 J. The barrel of the gun is 50 cm long. The gun has a mass of 4 kg, the bullet 10 g. (a) Find the bullets final velocity. (b) Find the bullets final momentum. (c) Find the momentum of the recoiling gun. (d) Find...
  37. Kmol6

    Linear momentum - Bullet fired vertically

    Homework Statement A bullet is fired vertically into a 1.40 kg block of wood at rest directly above it. If the bullet has a mass of 29.0 g and a speed of 510 m/s, how high will the block rise after the bullet becomes embedded in it? Homework Equations 1. m1v1 +m2v2 = mfvf 2. x=xo +vot...
  38. T

    Equations associated with calculating velocity of a bullet.

    Hello, I'm currently doing a project on a Verne gun, and I'd just like to know which equations I should know in order to explain such a device. How do i calculate velocity, efficiency of the launch, how the gas laws play into the efficiency, since it should be traveling at 10s of kilometers a...
  39. normal_force

    Physics of bullet impacts, I wonder if anyone can help?

    If I have a bullet with 700 Joules KE, the mass is 0.008036m, velocity 417.39m/s, momentum p=3.35kg-m/s Kinetic energy is the ability to do work, Kinetic energy converts into FORCE...so yes KE will exert a force...which will do work, as to do work requires force and distance. Thus, when the...
  40. R

    Speed of a Bullet: Hunter's Rifle & Duck Flight

    Homework Statement A hunter’s rifle is pointed upwards in a vertical position aiming at a duck flying 50 m above the gun. The bullet has a weight of 5 N and it is shot moving upward with a speed of 40 m/s when it hits the duck. (a) What is the speed of the bullet as it leaves the rifle? (b)...
  41. C

    Does the bullet reach its target?

    Homework Statement As outlaws escape in their getaway car, which goes 3/4c, the police officer fires a bullet from a pursuit car, which only goes 1/2c. The muzzle velocity of the bullet (relative to the gun) is 1/3c. Does the bullet reach its target according to Galileo? According to Einstein...
  42. M

    Does initial speed of a gun affect bullet velocity?

    My brother and I were having an argument so I decided to make an account on this forum. Say you were to lurch you hand forward while firing a pistol. Would that affect the max velocity of the bullet?
  43. Verrine

    How Does Bullet Velocity Change After Passing Through Different Block Widths?

    Homework Statement A bullet goes through a block and covers a distance D with a velocity of V0=200m/s. Calculate the velocity that the same bullet has AFTER passing through another block of the same material but which has half the width of the initial block. Homework EquationsThe Attempt at a...
  44. N

    Bullet camera in PVC pipe condensation problems -- Help please

    I had to installed some IP bullet cameras in some PVC pipe on a Hopper dredge to protect it from the salt water spray. They are outdoor cameras but they are made out of aluminum and they will rust if left unprotected. I sealed them in the pvc and used a cgb from the wire as well as sealant on...
  45. RandyD123

    Bullet Velocity Experiment: Does a Fired or Dropped Bullet Hit the Ground First?

    If a bullet is fired from a gun perfectly parallel to the ground and a bullet is dropped from that same height at the same time which one hits the ground first? Sorry for the two late edits. 1. The gun is not dropped, the gun is locked in a vice and perfectly level to the ground. 2. The bullet...
  46. T

    Bullet acceleration into moist clay

    The problem: A bullet is moving at a speed of 367 m/s when it embeds into a lump of moist clay. The bullet penetrates for a distance of 0.0621m. Determine the acceleration of the bullet while moving into the clay. I can get the correct answer by using Vf2 = Vi2 + 2ad (result: -1.08*10-6 m/s2)...
  47. jcruise322

    Conservation of angular momentum of disk and bullet system

    I know that the angular momentum is conserved in the below example, but intuitively I am struggling. Anyway, here goes! Homework Statement A bullet that is traveling without spinning hits and sticks into a filled disk tilted on its side an arbitrary distance "d" away from the center of mass...
  48. T

    How fast to shoot a bullet for it to hit the moon?

    Ignoring the fact that the atmospheric friction would probably disintegrate it. I know that to achieve LEO takes around 10km/s delta v. But only 2km/s of that is to overcome the drag and gravity. So you could shoot at 2km/s, get to LEO altitude then it falls back down because it is not at...
  49. A

    Simple harmonic motion: mass on a spring is hit by a bullet

    Homework Statement A 4.0kg block is suspended from a spring with force constant of 500N/m. A 50g bullet is fired into the block from directly below with a speed of 150m/s and is imbedded in the block. Find the amplitude of the resulting simple harmonic motion. Homework Equations F=-kx...
  50. Earnest Guest

    A Why should the Bullet Cluster focus light?

    In the Bullet Cluster, we have two well defined galaxy clusters that exhibit gravity lensing. Between them is a mass of gas (mostly hydrogen and helium) that is roughly eight to nine times the stellar (observable) mass of the two galaxies. The mass of gas doesn't exhibit any lensing. My question...
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