48 terms

# Physics 9 cp 2 & 3

#### Terms in this set (...)

An object in mechanical equilibrium is
Stable without changes in motion
Force is needed to
Change an objects state of motion
Force
Push or pull
Net force
Combination of all forces acting on an object
What is the net force of something that isn't moving
Zero
Scientific unit of force
Newton (N)
Tension
A stretching force
Weight
Force of gravity acting downward
Vector
Name of the arrow that represents the magnitude and direction of a quantity
Vector quantity
Needs both magnitude and direction
Scalar quantity
Described by only magnitude not direction
Example of scalar quantity
Time, area, volume
Example of vector quantity
Force
Mechanical equlibrium rule
M(sideways)F=0
Mechanical equilibrium
State of which no physical changes occur
Equilibrium rule
When the net force is 0 the object is in mechanical equilibrium
Support force on an object at rest =
The objects weight
Support force
Upward force that balances the weight of an object on a surface
Support force is sometimes called
Normal force
Upward forces are
Positive
Downward forces are
Negative
Static equilibrium
Object is at rest
Dynamic equilibrium
Objects moving at a constant speed in the same direction
Equilibrium
State of no change
Two kinds of mechanical equilibrium
Static equilibrium dynamic equilibrium
The parallelogram rule
To find the result of two nonparallel vectors construct a parallelogram
Resultant
Sum of two or more vectors
The result of rope tension is equal to
The objects weight
What are Aristotle's two types of motion
Natural and violet motion
Formula for mass
Weight times 10
Formula for weight
Mass divided by 10
Natural motion is
straight up or straight down
Violent motion
Imposed motion a result of forces being pushed or pulled
Calpunicus proposed
Earth orbited the sun
Calpunicus idea about earth orbiting the sun was
controversial
Galileo idea
only when fricition is present a force is needed to keep an object moving
Galileo on force
it is not necessary to keep an object moving
fricition
a force acting between materials that touch as they move past each other
inertia
the property of a body to resist change to its state of motion
newtons first law states
every object continues in a state of rest or a uniform speed in a straight line unless acted upon by a non-zero net force (unbalanced object)
newtons first law called
law of inertia
to set an object in motion
a force is needed
mass is a measure of
inertia
the more mass an object has
the greater its inertia, the harder it is to change its state of motion
mass is measured in
kilograms (kg)
weight
the force of gravity on an object
weight is affected by
the objects location
newtons work showed
that objects on earth move with earth
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