physical science a unit 2

force

push or pull

net force

total forces acting on an object

newton (N)

units force is measured in

unbalanced forces

do not add up to zero

balanced forces

cancel each other out, add up to zero

inertia

mass allows object to stay at rest or stay in motion

objects with lots of mass

have lots of inertia

objects with tiny mass

have small amount of inertia

friction 

a force that happens in opposite direction of motion

mass

amount of “stuff” (matter) in an object

weight

mass and gravity of an object

gravity

force between any objects that have mass

Newton’s First Law

An object in motion will stay in motion, object at rest will stay at rest unless acted on by an outside force

Newton’s Second Law

F=ma BIG MASS= tiny acceleration small mass = BIG ACCELERATION

Newton’s Third Law

For every action, there is an equal an opposite reaction

Law of Universal Gravitation

more mass= more gravity

less mass = less gravity

closer together = more gravity

farther apart = less gravity

momentum

measure of mass in motion p=mv