Please choose the correct ending to complete the given sentence: Education and Communications: [header] How to calculate the distance traveled by an object using vector kinematics [title] Determine the angle which the bullet is fired, relative to the ground. [step] This can be done using a simple mathematical compass. [title] Determine the initial (starting) velocity of the bullet as soon as it leaves the barrel of the gun.

Ending1: [title] Decide the distance traveling in either direction. [step] This can be done simply by dividing the bullet area by the degrees of relative velocity. Ending2: [step] Convert the distance traveled by the bullet to the actual velocity. Otherwise the problem will become much more complex. Ending3: [step] This information can usually be found on the gun's package or the manufacturer's website. The initial velocity of the projectile varies, depending on the gun model and ammunition type. Ending4: [step] ( where? ) [title] Determine the subsequent velocity after the bullet strikes the ground. [step] It's common to multiply the distance elapsed by the velocity during an initial flight of a bullet.

Answer format: ending1/ending2/ending3/ending4