newton's first law of motion
INERTIA!
definition of the law of inertia
? Every object continues in a state of rest, or of motion, in a straight line at a constant speed, unless it is compelled to change that state by forces exerted upon it
? An object in motion tends to stay in motion, and an object at rest tends to stay at rest
mass is
- a measure of inertia
- the quantity of matter in an object
- the same in all locations
the SI unit of mass
the kilogram
weight is
- a measure of the gravitational force action on the object
- depends on the object's location
EQUATION
weight = mass(acceleration due to gravity)
BASICALLY: w = mg
SI unit of force
the Newton
conversions
one kilogram = 9.8 Newton = 2.2 pounds
equilibrium
at rest
(when the net force acting on an object is ZERO)
the net force
the combination of all forces acting on an object
law of inertia states that an object...
- will keep moving at the same velocity unless an outside force acts on it
- at rest will remain at rest unless acted on by an outside force
- that is not moving will never move unless a force acts on it
- will continue moving in a straight line unless an outside force acts on it
if one object has 2x as much mass as another...
the first also has TWICE as much INERTIA!
more mass = more inertia
which has more mass, a kg of feathers, or of iron?
SAME
sheet of paper can be drawn from under a container of milk w/o toppling it. WHY?
because the milk carton has INERTIA.
that object at rest wanted to stay at rest!!! :D