Kinetic fundamentals
Force: Quantitatively, force is equal to a bodies mass times its acceleration.
- Force = mass × acceleration or F = m × a or F = ma.
- The units of force are in honor of the person who formulated the equation; Isaac Newton, therefore 1kg x 1m/s/s = 1 Newton (N).
- 1lb = 4.45 N.
- Forces that act within a body are called internal forces. Internal Knee Forces
- Forces that act on a body like those illustrated below are called external forces
- What happens to acceleration if force remains the same and mass is halved?
- What happens to acceleration if force remains the same and mass is doubled?
The equation above tells us more than just what influences force. The equation tells us that, assuming mass remains constant, the greater the force the greater the acceleration. In other words, the force equation is a connection between motion (kinematics) and what causes motion (forces or kinetics).
The equation also shows that acceleration is inversely proportional to mass.