To provide protection to the player, a football helmet receives the initial blow and begins to move, the padding inside the helmet compresses slowly thus slightly delaying the movement of the player's head. the player's head begins to move but accelerates slower than the helmet Impact equals the change in momentum (velocity x mass). The less impact received, the less pain and injury conveyed to the player. Acceleration is the rate at which velocity changes and is proportional (via mass) to momentum. Thus, the lower the , the more protection provided by the helmet and less damage sustained by the player.