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Newton's Laws of Motion

  • First law: an object continues in its state of rest or uniform motion unless an external force acts on it.
  • Second law: the net force acting on an object is equal to the mass of the object times its acceleration: F = ma. The force F is in Newtons (N), the mass m is in kilograms (kg), and the acceleration is in m/s2.
  • Third law, the law of action and reaction: If particle 1 exerts a force on particle 2, then particle 2 exerts an equal but opposite force on particle 1.
  • The weight of an object is the force of gravity exerted on the object by the Earth. It has to be clearly distinguished from the mass.
  • When an object moves on a rough surface, a frictional force always opposes the motion. If the object is stationary, a force of static friction acts on it with a magnitude that varies from zero to a maximum value.

Newton's Laws of Motion

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

AP Physics B