<p>Robert recently watched a documentary on the Fairchild-Republic A-10 Thunderbolt II (‘Warthog’). This single-seat close air support aircraft is entirely designed around a seven-barrel 30mm GAU-8/A Avenger Gatling gun that fires 3900 rounds (bullets) per minute with a muzzle velocity of approximately 3250 ft/s to engage armored targets (especially tanks) at distances approaching two miles. Aluminum jacketed combat ammunition loads use a 4 to 1 ratio of depleted uranium (DU) armor-piercing incendiary (API) and high-explosive incendiary (HEI); rounds are typically 11.4 in long and mass 1.53+ lb. The rated accuracy specifies 80% of the fired rounds impact within a 20ft radius circle 4000ft downrange, with a drop of 10ft. Due to the enormous recoil of this gun (and to conserve ammunition), pilots typically fire the cannon in 2.00s bursts. Using SI units, calculate the engine thrust necessary to maintain constant airspeed during the interval when the cannon fires. Assume the plane is in level flight and that 56% of the mass of each round is the projectile (each API projectile contains a 0.66lb DU sabot in a Ti-Al jacket)<br /><br />Note: All momentum analyses must begin with a FBD*, include an isolation test, and utilize the law of momentum conservation.</p>
<p>Robert recently watched a documentary on the Fairchild-Republic A-10 Thunderbolt II (‘Warthog’). This single-seat close air support aircraft is entirely designed around a seven-barrel 30mm GAU-8/A Avenger Gatling gun that fires 3900 rounds (bullets) per minute with a muzzle velocity of approximately 3250 ft/s to engage armored targets (especially tanks) at distances approaching two miles. Aluminum jacketed combat ammunition loads use a 4 to 1 ratio of depleted uranium (DU) armor-piercing incendiary (API) and high-explosive incendiary (HEI); rounds are typically 11.4 in long and mass 1.53+ lb. The rated accuracy specifies 80% of the fired rounds impact within a 20ft radius circle 4000ft downrange, with a drop of 10ft. Due to the enormous recoil of this gun (and to conserve ammunition), pilots typically fire the cannon in 2.00s bursts. Using SI units, calculate the engine thrust necessary to maintain constant airspeed during the interval when the cannon fires. Assume the plane is in level flight and that 56% of the mass of each round is the projectile (each API projectile contains a 0.66lb DU sabot in a Ti-Al jacket)<br /><br />Note: All momentum analyses must begin with a FBD*, include an isolation test, and utilize the law of momentum conservation.</p>
