A projectile is an object that is propelled by the application of an external force and then moves freely under the influence of gravity and air resistance.[1] [2] Although any objects in motion through space are projectiles, they are commonly found in warfare and sports (for example, a thrown baseball, kicked football, fired bullet, shot arrow, stone released from catapult).[3] [4]
In ballistics mathematical equations of motion are used to analyze projectile trajectories through launch, flight, and impact.
See also: Projectile motion.
Blowguns and pneumatic rifles use compressed gases, while most other guns and cannons utilize expanding gases liberated by sudden chemical reactions by propellants like smokeless powder. Light-gas guns use a combination of these mechanisms.
Railguns utilize electromagnetic fields to provide a constant acceleration along the entire length of the device, greatly increasing the muzzle velocity.
Some projectiles provide propulsion during flight by means of a rocket engine or jet engine. In military terminology, a rocket is unguided, while a missile is guided. Note the two meanings of "rocket" (weapon and engine): an ICBM is a guided missile with a rocket engine.
An explosion, whether or not by a weapon, causes the debris to act as multiple high velocity projectiles. An explosive weapon or device may also be designed to produce many high velocity projectiles by the break-up of its casing; these are correctly termed fragments.
In projectile motion the most important force applied to the ‘projectile’ is the propelling force, in this case the propelling forces are the muscles that act upon the ball to make it move, and the stronger the force applied, the more propelling force, which means the projectile (the ball) will travel farther. See pitching, bowling.
Many projectiles, e.g. shells, may carry an explosive charge or another chemical or biological substance. Aside from explosive payload, a projectile can be designed to cause special damage, e.g. fire (see also early thermal weapons), or poisoning (see also arrow poison).
Some projectiles stay connected by a cable to the launch equipment after launching it:
See also: Orders of magnitude (speed) and Muzzle velocity.
| Projectile | Speed | Specific kinetic energy (J/kg) | ||||
|---|---|---|---|---|---|---|
| (m/s) | (km/h) | (ft/s) | (mph) | |||
| Object falling 1 m (in vacuum, at Earth's surface) | 4.43 | 15.948 | 14.5 | 9.9 | 9.8 | |
| Object falling 10 m (in vacuum, at Earth's surface) | 14 | 50.4 | 46 | 31 | 98 | |
| Thrown club (expert thrower) | 40 | 144 | 130 | 90 | 800 | |
| Object falling 100 m (in vacuum, at Earth's surface) | 45 | 162 | 150 | 100 | 980 | |
| Refined (flexible) atlatl dart (expert thrower) | 45 | 162 | 150 | 100 | 1,000 | |
| Ice hockey puck (slapshot, professional player) | 50 | 180 | 165 | 110 | 1,300 | |
| 80-lb-draw pistol crossbow bolt | 58 | 208.8 | 190 | 130 | 1,700 | |
| 63 | 228.2 | 208 | 141 | 2,000 | ||
| 87 | 313.2 | 285 | 194.6 | 3,785 | ||
| Paintball fired from marker | 91 | 327.6 | 300 | 204 | 4,100 | |
| 175-lb-draw crossbow bolt | 97 | 349.2 | 320 | 217 | 4,700 | |
| 100 | 360 | 328 | 224 | 5,000 | ||
| Air Rifle BB 4.5 mm | 150 | 540 | 492 | 336 | 11,000 | |
| Air gun pellet .177" (magnum-power air rifle) | 305 | 878.4 | 1,000 | 545 | 29,800 | |
| 9×19mm (bullet of a pistol) | 340 | 1224 | 1,116 | 761 | 58,000 | |
| 12.7×99 mm (bullet of a heavy machine gun) | 800 | 2,880 | 2,625 | 1,790 | 320,000 | |
| German Tiger I 88 mm (tank shell- Pzgr. 39 APCBCHE) | 810 | 2,899 | 2,657 | 1,812 | 328,050 | |
| 5.56×45mm (standard round used in many modern rifles) | 920 | 3,312 | 3,018 | 2,058 | 470,000 | |
| 20×102mm (standard US cannon round used in fighter cannons) | 1,039 | 3,741 | 3,410 | 2,325 | 540,000 | |
| 25×140mm (APFSDS, tank penetrator) | 1,700 | 6,120 | 5,577 | 3,803 | 1,400,000 | |
| 2 kg tungsten Slug (from Experimental Railgun) | 3,000 | 10,800 | 9,843 | 6,711 | 4,500,000 | |
| Up to 4,000 | Up to 14,000 | Up to 13,000 | Up to 9,000 | Up to 8,000,000 | ||
| Up to 7,000 | Up to 25,000 | Up to 23,000 | Up to 16,000 | Up to 24,000,000 | ||
| 8,000 | 29,000 | 26,000 | 19,000 | 32,000,000 | ||
| ~10,000 | ~36,000 | ~33,000 | ~22,000 | ~50,000,000 | ||
| 0–16,000 | ~58,000 | ~53,000 | ~36,000 | ~130,000,000 | ||
| 7 TeV particle in LHC[5] | 299,792,455 [6] | 1,079,252,839 | 983571079 | 670,616,536 | ~6.7 × 1020 [7] | |
See main article: Projectile motion. An object projected at an angle to the horizontal has both the vertical and horizontal components of velocity. The vertical component of the velocity on the y-axis is given as
Vy=U\sin\theta
Vx=U\cos\theta
\theta
1. Time to reach maximum height. It is symbolized as (
t
t=U\sin\theta/g
g
U
\theta
2. Time of flight (
T
T=2U\sin\theta/g
3. Maximum Height (
H
H=U2\sin2\theta/2g
4. Range (
R
R=U2\sin2\theta/g
\theta
\sin2\theta=1