### alteration:

Acceleration
* All accelerations are caused by a net force acting on an object.
* Most acceleration is caused by forces.
* Some acceleration is caused by gravity.
  * is the change of velocity divided by the change of time. Acceleration vector, and therefore includes both a size and a direction.
* also increases the electron current flowing between the atmosphere and magnetosphere.
* are outside the realm of special relativity and require general relativity.
* can be due to a change in speed or a change in direction.
* change in speed or direction of motion
  - the velocity an object is moving, either increase or decrease
  - velocity over a change in time
  - velocity, where it's a change in magnitude or a change in direction
* changes over time.
* depends on force and mass.
* equals force divided by mass.
* has to do with changing how fast an object is moving.
* increases after the resistance afforded by earth's atmosphere has been left behind.
* is also a vector quantity and it is in the same direction as the force
  - an occurrence
  - calculated as velocity divided by time
* is directly proportional to net force
  - the applied net force
  - equal to the change in velocity divided by the change in time
  - how fast velocity changes
  - indicated by the tilting of the pendulum and of the water surface
  - inversely proportional to mass
  - nothing else but a force acting on a particle
  - produced when a force acts on a mass
  - proportional to force
  - related to injury
  - the change in speed during a certain period of time
* is the change in velocity per unit of time
  - with respect to time
  - of location per second per second
  - in one second
  - increase in speed or velocity over a period of time
* is the rate at which speed changes
  - the gas escapes
* is the rate at which velocity changes
  - or speed changes with time
* is the rate of change of the speed at which the body part moves
  - the velocity of an object
  - velocity with time
  - that the velocity is changing
  - result of an unbalanced force acting on the object
  - same as velocity
* is the second derivative of distance or length with respect to time
  - position with respect to time
* is the slope of the velocity curve at a certain point
  - velocity-time curve
  - time rate at which a velocity is changing
* major use of gas.
* measure of change in speed, or simply the effect of gravity on stationary objects
  - the rate of change of velocity of an object
* measurement of both the change in speed and the change in direction of an object.
* occurs anytime an object's speed increases or decreases, or it changes direction
  - whenever velocity changes
  - where streamlines change direction
* physical measure of the instantaneous motion at some point on the earth's surface.
* produces inertial forces.
* seems to be at the root of motion as far as kinematics is concerned.
* sign of healing.
* takes places.
* vanishes only when the rate of change of the velocity vector is zero.
* vector , and therefore includes both a size and a direction
  - quantity that indicates the rate of change of velocity
  - requiring both magnitude and direction
* vital part of studying certain principles in physics.
+ Acceleration, Finding acceleration, Other words
  * Acceleration can be positive or negative. For example, when a car brakes it decelerates
  - acceleration: Basic physics ideas :: Mechanics

### alteration | acceleration:

Angular acceleration
* change in angular velocity.
* is acceleration
  - how fast the angular velocity is changing

Average acceleration
* is acceleration measured over a non-zero time interval
  - the change in an object's velocity during some elapsed time
* quantity calculated from two velocity measurements.

Constant acceleration
* are represented as straight lines.
* is completely equivalent to a uniform gravitational field
  - the motion that occurs quite often in nature