CH 5 Lecture Slides: Newton's third law of motion

interaction

• between one thing and another

• pair of forces acting on two objects

• ex: interaction of hand and wall pushing on each other

force pair

you push on wall; wall pushes on you

newton’s third law of motion

Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.

every action has a

equal and opposite reaction

action and reaction forces

• always act on different objects (effects don’t cancel)

• ex: car crash

simple rule to identify action and reaction

identify the interaction- one thing interacts with another

newton’s first law

• inertia

• object at rest remains at rest unless acted upon by outside forces

newton’s second law

• acceleration

• when a net force acts on an object it will accelerate

vector quantity

• magnitude and direction

• represented by an arrow

• velocity, force, acceleration

scalar quantity

• has magnitude

• mass, volume, speed

resultant

the sum of two or more vectors

two vectors that don’t act in the same or opposite direction

us parallelogram rules

two vectors at right angles to each other

• use Pythagorean theorem

• R² = V² + H²

for a given vector one can break it into

the X and Y components

Vector components

• vertical and horizontal components of a vector are perpendicular to each other

• determined by resolution