A certain 8lb hunting rifle fires a 180 grain bullet at a target 1000yds away. The bullet experiences an acceleration of -2.7 m/s2 (opposite direction of velocity) due to air resistance. When the bullet hits the target, its velocity is measured to be 820 m s. Express all answers in SI units. Helpful conversions:
1 grain = 6.48 x 10-5 kg 1m = 3.281 ft
a mass of 1kg weighs 2.2075 pounds (at the surface of the earth)
(a) What is the rifle's muzzle velocity (the velocity the bullet has as it leaves the rifle barrel)?
(b) What is the recoil velocity of the rifle?
(c) Neglecting energy lost to heat and the rotation of the bullet, how much internal energy was required to fire the bullet?
(d) Assuming the bullet leaves the gun with a perfectly horizontal velocity, and that the air resistance is also horizontal, how far has the bullet fallen when it hits the target?