Pre-modern medicine: Scientific revolution Laws of motion: 1. First law: law of Inertia 2. Second law f=ma 3. Thirdly Action=Reaction Universal gravitation Philosophiae Naturalis Principia Mathematica( Mathematical Principle of Natural Philosophy )1897 Isaac Newton 1642-1727 obst a eitherat rest f ts eoe ty sequal to zero it moves woth onstant speed in a single direction. 天不生牛顿,万古如长夜 Second law: The acceleration a of a body is parallel and directly proportional to the net force F acting on the body, is in the direction of the net force, and is Nature and nature s law lay hid in light, inversely proportional to the mass m of the body,ie, F=ma God said, let Newton be! And alwas light. Third aw when a first body exerts a force Fi on a secnd body, the second means 级乒 f and F2 are equalin magnitude and opposite in direPre-modern Medicine: Scientific revolution Isaac Newton 1642-1727 天不生牛顿， 万古如长夜 Nature and nature’s law lay hid in light, God said, let Newton be! And all was light. Laws of Motion: 1. First law: Law of Inertia 2. Second law F=ma 3. Third law: Action=Reaction Universal Gravitation First law: If there is no net force on an object, then its velocity is constant. The object is either at rest (if its velocity is equal to zero), or it moves with constant speed in a single direction.[ Second law: The acceleration a of a body is parallel and directly proportional to the net force F acting on the body, is in the direction of the net force, and is inversely proportional to the mass m of the body, i.e., F = ma. Third law: When a first body exerts a force F1 on a second body, the second body simultaneously exerts a force F2 = −F1 on the first body. This means that F1 and F2 are equal in magnitude and opposite in direction. Philosophiæ Naturalis Principia Mathematica ( Mathematical Principles of Natural Philosophy）1897