A piece of clay is attached to an air cart. A BB gun is used to shoot a bullet at the clay, causing the system to move. The velocity of the recoiling cart is measured using a photogate. The mass of the bullet is determined by weighing an identical bullet and the mass of the clay and cart are determined using a scale. The measured masses and velocity are used to calculate the initial velocity of the bullet.
NOTE: The BB gun MUST be fired HOIZONTALLY, parallel to the track.