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## Ignore words

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kinematics
branch of mechanics that explains the "what" and "how" of motion
motion
An object is moving if its position relative to a fixed point is changing.
subscripts
clarify variables specific cases of variables
Greek letters
have special meanings and functions, constants and variables
frame of reference
assists one in physics in which one chooses a place (point) a measure it against changes in position.
Distance
a path taken and always a positive number
displacement
A change in position (delta p).
Speed
Units: cm/s, m/s, mi/hr, km/s ...
Velocity
a speed in a particular direction.
epistemology
a way of knowing
empircism
truth comes from comparing out ideas with the world
reductionism
to understand a complicated whole you must first understand the sum of their parts
scientific theory
fits together many hypothesis and suggests more
matter, motion, causes
What are the core concepts of physics
theoretical physics and experimental physics
What are the two vantage points on physics
theoretical physics
starts from math and predicts what will happen
experimental physics
starts with reality and suggests why it is
units of measure
set a standard and let us measure in between the discrete counting units
precisions
repeatedly getting the same value
scalar
a physical quantity that has magnitude but no direction
vector
a displacement distinguished by magnitude and direction but not by location.
acceleration
(physics) a rate of change of velocity
Instantaneous Speed
Magnitude of instantaneous velocity
Average Speed
Distance traveled divided by the time required to cover the distance
Constant Acceleration
The acceleration of an object is proportional to force (F = ma) - thus, if there is a constant force applied onto an object, the object will accelerate at a constant rate.
s=d/t
Speed equation
Velocity Equation
- Don't need to memorize, just understand conceptually.
Acceleration equation
a = change in v / t
rise (delta y)
The vertical separation of any two points on a curve is the _______
Time Interval
A measurement of time is a _______
run (delta x)
The horizontal separation of any two points on a curve is the _______
constant velocity
An object that has the same average velocity for all time intervals is moving at _______
slope
On a X vs. t graph, the velocity is represented by the_
Average Velocity
Dividing displacement by elapsed time
initial velocity
The velocity when the clock reading is zero is the _______
final velocity
The velocity after acceleration has occurred is the _______
acceleration due to gravity (g)
The constant acceleration that acts on falling bodies is _______
Instantaneous Velocity
How fast an object is moving and direction of motion at each instant in time
seconds (s)
The units of time
The units of speed
meters per second (m/s)
The units of acceleration
meters per second squared (m/s^2)
multiply by 3.6
To convert from m/s to km/h
divide by 3.6
To convert from km/h to m/s
speeding up
If the sign of the velocity and the acceleration is the same then the object is_______
slowing down
If the sign of the velocity and the acceleration is the opposite then the object is_______
g = 9.8 m/s^2
If the object is thrown downwards then_______
g = - 9.8 m/s^2
If the object is thrown upwards then_______
Meter (m)
SI unit Length
Kilogram (kg)
SI unit Mass
Newton (N)
SI unit Force
Second (s)
SI unit Time
Joule (J)
SI unit Work and Energy
Watt (W)
SI unit Power
Liter (L)
SI unit Volume
Nanometer (nm)
SI unit subatomic level Length 10^-9 m
giga (G)
Multiples Factor 10^9
mega (M)
Multiples Factor 10^6
kilo (K)
Multiples Factor 10^3
centi (c)
Multiples Factor 10^-2
milli (m)
Multiples Factor 10^-3
micro (m)
Multiples Factor 10^-6
nano (n)
Multiples Factor 10^-9
pico (p)
Multiples Factor 10^-12
v cos theta
Given Vector V find x component
v sin theta
Given Vector V find y component
Instantaneous acceleration
Average acceleration as change in time approaches 0
Average acceleration
a = ∆v/∆t
weight
A force that comes from gravity pulling down on any object with mass
mass
a body of coherent matter, usually of indefinite shape and often of considerable size
Newtons First Law
A body at rest or in constant motion will remain that way unless a force acts on it
Newtons Second Law
A law of motion that states that acceleration is equal to force divided by mass.
Newtons Third Law
A law of motion that states that for every action force here is a reaction force equal in strength and opposite in direction.
Translational Motion
Motion where there is no rotation
Rotational Motion
Forces applied to an object cause the object to rotate around a fixed point (fulcrum)
Torque
A "force" that causes rotation because it is exerted at a distance from the axis of rotation.
In uniform circular motion, what is the magnitude of the tangential force? and why?
Zero because there is no change in speed of the object because its constant.
The radial force because the tangential force is zero
What is the resultant force of an object moving in uniform circular motion?
Resultant Force
If two or more force vectors are added, then the result is a_______
What are the two kinds of friction?
Static friction (not moving) and Kinetic friction (moving)
static friction
A car drives with its tires rolling freely. Is the friction between the tires and the road kinetic or static?
Kinetic Friction
Friction between moving surfaces
How are the Kinetic friction and Static Friction equations different?
The kinetic friction equation has an equal sign the static friction equation has a less than or equal to sign meaning kinetic friction will have constant value for any given combination of coefficient of kinetic friction and normal force
Which will have a higher maximum value static friction or constant kinetic friction?
static friction it takes more force to move something than to get an object to slide and keep it sliding