Frame of Reference
a system for specifying the precise location of objects in space and time
Motion
an object's change in position relative to a reference point
distance
measures the path taken (total)
displacement
measures the change in position (includes direction)
speed
how fast an object moves (scaler)
velocity
both the speed and the direction an object moves (vector)
calculating speed
distance/time
calculating velocity
displacement/time
speed graph
distance vs. time
Instantaneous Speed
speed at a given time and position
Slope (Speed)
change in distance/change in time
acceleration
the rate at which velocity changes over time
speeds up, slows down, changes direction
acceleration is when an object _______ (3 things)
acceleration =
change in velocity/time
centripetal acceleration
The acceleration that occurs in a circular motion is known as _________. (2 words)
average acceleration =
final velocity-initial velocity/time
acceleration graph
speed vs. time
Newton's First Law
objects change their state of motion only when a net force is applied
Net force
total amount of force
mass
Inertia is related to an object's _____.
Inertia
the tendency of an object to resist a change in motion unless an outside force acts on the object
Newton's Second Law
Net force is equal to mass times acceleration. The unbalanced force on an object determines how much an object speeds up or slows down.
F =
ma
W =
mg
Weight
a measure of the gravitational force exerted on an objects
Fg =
G (m1*m2/d squared)
Free fall
the motion of a body when only the force of gravity is acting on the body
Terminal Velocity
the constant velocity of a falling object when the force of air resistance is equal in magnitude and opposite in direction to the force of gravity
Projectile Motion
the curved path that an object follows when thrown, launched, or otherwise projected near the surface of Earth
horizontal & vertical
Projectile motion has two components --
Newton's Third Law
For every action, there's an equal and opposite reaction
Momentum (p) =
m*v
Momentum
quantity defined as the product of the mass & velocity of an object
kg * m/s
Unit for momentum
Law of Conservation of Momentum
The total momentum of two or more objects after a collision is the same as it was before the collision.
Conservation of Momentum Formula
(m1v1) + (m2v2) = (m1bv1b) + (m2bv2b)
Work
the transfer of energy to an object by the application of a force that causes the object to move in the direction of the force
Work =
f*d
Joules
units for work
Power
the rate at which word is done, or how much work si done in a given amount of time
Power =
work/time
Watts
unit for power
Mechanical Advantage
a quantity that expresses how much a machine multiplies force or distance
Mechanical Advantage =
output force/input force; input distance/output distance
Lever & Inclined Plane
Two families of simple machines: _______ & ________
Lever family
simple lever, pulley, wheel & axle
Inclined Plane family
simple inclined plane (ramp), wedge, screw
energy
the capacity to do work
joules
unit for energy
Potential energy
the energy that an object has because of the position, shape, or condition of the object
elastic potential energy
Any object that is stretched or compressed to increase or decrease the distance between its parts has ____________.
gravitational potential energy
Any system of two or more objects separated by a vertical distance has ___________.
Grav. PE =
mgh
Kinetic energy
the energy of an object due to the object's motion
KE =
m/2 * v squared
Law of Conservation of Energy
Energy cannot be created or destroyed. The total amount of energy in the world never changes, although energy may change from one form to another.
mechanical energy
the amount of work an object can do because of the object's kinetic & potential energies
temperature
a measure of how hot (or cold) something is
thermometer
an instrument that measures and indicates temperature
Fahrenheit, Celsius, & Kelvin
The three main temperature scales: ________
Fahrenheit Boiling Temp.
212 degrees F
Fahrenheit Freezing Temp.
32 degrees F
Celsius Boiling Temp.
100 degrees C
Celsius Freezing Temp.
0 degrees C
Celsius to Fahrenheit Formula
1.8 * Tc + 32
Fahrenheit to Celsius Formula
Tf - 32/1.8
Celsius to Kelvin Formula
Tc + 273
Kelvin to Celsius Formula
Tk - 273
Absolute Zero
the temperature at which molecular energy is at a minimum
Heat
the energy transferred between objects that are at different temperatures
Conduction, Convection, & Radiation
What are the three ways that energy transfers?
thermal conduction
the transfer of energy as heat through a material
convection
the movement of matter due to differences in density that are caused by temperature variations
convection current
any movement of matter that results from differences in density; may be vertical, circular, or cyclical
radiation
the energy that is transferred as electromagnetic waves, such as visible light and infrared waves
conductor
a material through which energy can be easily transferred as heat
insulator
a material that transfers energy poorly
specific heat
the quantity of heat required to raise a unit mass of homogenous material 1K or 1*C in a specified way given constant pressure and volume
energy = mcAt
specific heat equation