# Shared Flashcard Set

## Details

Chapter 11
Chapter 11
42
Physics
02/13/2008

Term
 A frame of refernce is necessary to...
Definition
 to describe motion accurately and completely
Term
 Frame of reference-
Definition
 a system of objects that are not moving with respect to another
Term
 Relative motion-
Definition
 Relative motion-movement in relation to a frame of reference
Term
 Distance-
Definition
 length of a path between two points     When object moves in straight line, distance is length of line  connecting object’s starting point and ending point
Term
 What is the SI unit for measuring distance?
Definition
 meters(m)Very large distances-kilometers(km) Distances smaller than meter-centimeters(cm)
Term
 Displacement-
Definition
 direction from starting point and length of straight line from starting point to ending pointDisplacements sometimes used when giving directions.
Term
 Vector-
Definition
 quantity that has magnitude and direction Magnitude can be size, length, or amount
Term
Definition
Term
 You add two displacements, represented by vectors when they have ____ direction
Definition
 same
Term
 You subtract two magnitudes, when they are in ____ direction
Definition
 opposite
Term
 When two or more displacement vectors have different directions, they may be combined by
Definition
 graphing
Term
 resultant vector-
Definition
 vector sum of two or more vectors
Term
 speed-
Definition
 a.       ratio of distance that an object moves to amount of time the object moves
Term
 SI units of speed
Definition
 meters per second(m/s)    Need to choose units that make most sense for motion being described
Term
 average speed-
Definition
 computed for entire duration of trip
Term
 instantaneous speed-
Definition
 -measured at a particular instant-       rate at which object is moving at given moment in time                       Car’s speedometer gives your instantaneous speed
Term
 average speed formula:
Definition
 average speed= total distance                         total time  _ v= d     t
Term
 distance-time graph is a good way to describe ____
Definition
 motion
Term
 Slope of line on distance-time graph is the _____
Definition
 speed *Steaper slope on distance-time graph indicates higher speed
Term
 velocity-
Definition
 speed and direction in which an object is movinga vector
Term
 two or more velocities add by vector ___
Definition
Term
 acceleration-
Definition
 rate at which velocity changes       Acceleration can be described as changes in speed, changes in direction, or changes in both   a vector
Term
 Acceleration applies to any change in object’s _____
Definition
 velocitydecrease OR increase
Term
 free fall-
Definition
 movement of an object toward Earth solely because of gravity                     Example of acceleration due to change in speed
Term
 unit for acceleration:
Definition
 meters per second per second(m/s22)
Term
 free-fall acceleration:
Definition
 9.8 meters per second squared(9.8 m/s2)--> ~ 10 m/s2
Term
 You can still accelerate when speed is _____
Definition
 constant
Term
 Sometimes motion is characterized by changes in both _____ and _____ at the same time
Definition
 speed    direction
Term
 constant acceleration-
Definition
Term
 Velocity of an object moving in a straight line changes at a _______ when the object is experiencing constant acceleration.
Definition
 constant rate
Term
 You calculate acceleration for a straight-line motion by...
Definition
 diving change in velocity by total time
Term
 Acceleration formula:
Definition
 average acceleration=change in velocity                            total time _         a=Vf=Vi        t
Term
 If motion is in straight line, velocity can be treated as___
Definition
 speed
Term
 The slope of speed-time graph is the:
Definition
 acceleration
Term
 Constant acceleration represented on speed-time graph by
Definition
 straight line
Term
 Linear graph-
Definition
 displayed data form straight-line parts
Term
 Accelerated motion is represented by a ___ line on distance-time graph
Definition
 curved
Term
 Nonlinear graph-
Definition
 curve connects  plotted data points
Term
 instantaneous acceleration-
Definition
 how fast a velocity is changing at a specific instant.
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