physics unit 2 vocab: forces, dynamics, & newton’s laws

force

a vector quantity that measures a push or pull on an object with a specific magnitude and direction that can cause it to accelerate, measured in newtons (N)

push

a force that moves an object away from the source of force

pull

a force that moves an object toward the source of force

weight

a vector quantity that measures the force of gravity acting on an object's mass

mass

a scalar quantity that measures the amount of matter in an object

inertia

the tendency of an object to resist changes to its state of motion

vector

a quantity that has both direction and magnitude

resultant vector

the single vector that exhibits the sum of two or more vectors

resultant force

the sum of all forces acting on an object, added as vectors

newton's 1st law

a object at rest remains at rest or, if in motion, remains in motion at a constant speed in a straight line, unless acted on by an unbalanced, net external force; also known as the law of inertia

newton's 2nd law

the net force of an object is equal to its mass times its acceleration; the acceleration of an object depends on the mass and force acting on it

newton's 3rd law

for every action force, there is an equal and opposite reaction force

friction

an external force that acts opposite to motion or the tendency of motion between two surfaces in contact

sliding friction

the frictional force resisting motion when an object slides over a surface

contact friction

general term for friction between two objects in physical contact

air resistance

a type of frictional force that opposes motion through air (or gravity)

equilibrium

the state in which two opposing forces are balanced; the net force on an object is zero

dynamic equilibrium

state at which an object is moving at constant velocity because all forces are balanced

static equilibrium

state at which an object is at rest with all forces balanced

free-body diagram

a diagram showing all external forces acting on a single object

normal (support) force

the upward force a surface exerts on an object that is at rest, supporting its weight, and acting perpendicularly to and away from their plane of contact; the force that is opposite to gravity

force of gravity

the attractive force between any two masses near earth's surface; gives objects weight

elastic force

the force exerted by a stretched or compressed elastic object (like a spring)

tension force

the pulling force transmitted through a rope, string, cable, chain, or pulley system

applied force

a force that someone or something exerts on an object to move it, the force that is necessary to overcome friction

force of friction

the general resistance force (that is measured to be a constant value) of something moving or sliding

electromagnetic force

the fundamental force associated with charged particles; responsible for electric and magnetic effects, friction, and most contact forces

nuclear force

the strong force that holds the protons and neutrons together in an atomic nucleus