Demonstration of a Principle:
    Newton's Second Law, F=ma, or FEMA for short.
         Governs the motion of everything.

Demonstration:
 

Small Force, Small Motion	Big Force, Big Motion

    Do a degage from first position.
    Now do a grand battement from first position.
    Which takes more force?
    Why?

Answer:
    A grand battement requires more force.
    A small force (the degage) exerted on the limb produces small motion.
    A large force (the battement) produces large motion.

Reality Check:
    None required.  Sir Isaac Newton's second law is the simple explanation that explains  all motion, no matter how complex.

Extra Credit
Formula:
    F = m a         - for things that move in straight lines
    T = I t         - for things that spin

Means
    F = force             - pushing or pulling
    m = mass              - similar to weight, but doesn't require a planet to stand on
    a = acceleration   - how fast the speed is changing

    T = torque    - twisting force
    I = inertia - like mass, but for turning.  It depends on shape.  Like arms out, arms in.
    t = angular acceleration - how fast the speed of rotation changes