Newton’s Laws of Motion. AP Physics B Chapter 4 Notes. Newton’s First Law of Motion. Aristotle vs. Galileo Natural State of Motion Galileo Thought Experiment. Newton’s First Law of Motion.
AP Physics B Chapter 4 Notes
Galileo Thought Experiment
A force is a push or pull. An object at rest needs a force to get it moving; a moving object needs a force to change its velocity.
The magnitude of a force can be measured using a spring scale.
Every object continues in its state of rest, or of uniform velocity in a straight line, as long as no net force acts on it.
Common sense tells us…
The acceleration of an object is directly proportional to the net force acting on it, and is inversely proportional to its mass. The direction of the acceleration is in the direction of the net force acting on the object.
Action and reaction forces act on differentobjects!
Whenever one object exerts a force on a second object, the second exerts an equal force in the opposite direction on the first.
Subscript notation: First letter is what the force is acting on and the second letter is the source of the force.
Caution: Weight and normal force are not action-reaction pairs
Ffr = μFN
with μ equal to the coefficient of friction—a measure of the stickiness of the two surfaces
Break FG into x- and y-components