Biomechanics

• Newtons 1st law is a body continues in a state of rest or uniform velocity unless acted upon by a external or unbalanced force eg a 100m sprinter.
• Newtons 2nd law is a body rate of change in momentum is proportional to the size of the force applied and acts in the same direction as the force applied eg applied.
• Newtons 3rd law is for every action force applied to a body there is an equal and opposite reaction force eg 100m sprinter.
• Velocity - Rate of change in displacement (m/s)
• Velocity (m/s) = displacement (m) / time (s)
• Momentum - The quantity of motion possessed by a moving body
• Momentum (Kgm/s) = mass (kg) x velocity (m/s)
• Acceleration - Rate of change of velocity
• Acceleration (m/s^2) = change in velocity (m/s) / time (s)
• Force - A push or pull that alters the state of motion of a body
• Force (N) = mass (kg) x acceleration (m/s2)
• Internal force - Generated by the contraction of skeletal muscle
• External force - Comes from outside the body and acts upon it
• Net force is the sum of all forces acting on a body, also termed the resultant force. It is the overall force acting on a body when all individual forces have been considered.
• Balanced forces is when 2 or more forces acting on body are equal in size & opposite in direction. The net force = 0.
• Unbalanced forces is when 2 or more forces are unequal in size and opposite in direction. Net force will be present & the body will change state of motion.