Momentum = mass X velocity
Sports people talk about momentum usually when a collision takes place. The person with the least momentum ends up second best.
Tackles, collisions, involve forces that two or more players exert on one another due to their mass and momentum. These forces can be described by the three laws of motion developed by Sir Isaac Newton (1642–1727).
Newton's First law of motion states "That any object of mass at rest will stay at rest, and any object in motion will stay in motion at the same speed and direction unless acted upon by an external force.
Applied to football collisions, the more massive a football player the less likely he is to have his speed changed, or diverted by an outside force, such as a bump from an opponent. The first law is often called the law of inertia because the term inertia means the resistance to motion.
Tackles and blocks on the football field are governed by Newton's three laws of motion.
Lets first tackle the story of momentum. Momentum is the product of mass and velocity
momentum = mass(Kg) X vleocity (m/s)
Gridiron and rugby are sports of violent collisions and as you can see from the video on the right a player with a large mass travelling at speed is hard to stop. That is becasue he has a great deal of momentum.
Watch the video on the right. It is a fine example of momentum in sport. Notice the large player at the centre of the action. He brushes aside a player of considerably less mass than himself but is pushed back by a player with slightly less mass but travelling at greater speed. During the second collision the player, in white, increases his momentum, prior to the collision, by increasing his speed.