Gun and Bullet:

When you shoot a gun you fire the bullet in an arc. The arc we are examining in perfect. This makes the initial velocity and the final velocity's magnitudes equal. To calculate the momentum of the bullet you find the product of its mass and its final velocity. No kinematics are needed to find the momentum of the bullet. The equation for momentum was found at physicsclassroom.com The initial velocity of the bullet was found at mythbusterstheexhibition.com.

Photo Courtesy of Savanah Owen