# Biomechanics

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• Newtons Laws
• 1st Law
• 'The law of inertion'
• Example - a sprinter running at a constant speed, than any persons standing still
• The body continues in a state of rest or uniform velocity unless acted upon by an external force.
• 2nd Law
• When a force acts as an object, the rate of change of momentum experienced by the object is proportional to the size of the force and takes place in the direction in which the forces acts.
• Force = mass X acceleration
• E.g. A sprinter accelerating from his or her blocks.
• Longitudinal Axis
• The rotation runs from the top to the bottom of your body.
• Moment of inertia = relates to the distribution of mass about the axis in a spinning system. the further away from the axis the greater the mass, the greater the inertia and the harder it is to  spin.
• Causes a downward lift force to act on the ball.
• Projectiles
• Is the motion of an object in flight.
• Angle of release, Height of release and speed of release.
• The center of mass
• Is the single point in a body which represents all the spread out mass of a body.
• 100m sprint On your marks - base of support is wide with all of the  5 contact points. set - base of the support is the same but with 4 contact points.  Go - the base of support is much smaller with only 2 contact points