# Shared Flashcard Set

## Details

Physics
Midterm
61
Physics
01/20/2008

Term
 Physics
Definition
 the study of matter and energy and their relationships
Term
 Dimensional Analysis
Definition
 a method of treating units as algebraic quantities, which can be cancelled; can be used to check that an answer will be in the correct units
Term
 Significant Figures
Definition
 all the valid digits in a measurement, the number of which indicates the measurement’s precision all non-zero are significantleading zeros are notcaptive and trailing are
Term
 Scientific Method
Definition
 a systematic method of observing, experimenting, and analyzing to answer questions about the natural world
Term
 Hypothesis
Definition
 an educated, testable guess about how variables are related
Term
 Scientific Law
Definition
 a well-established rule about the natural world that sums up, but doesn’t explain, a pattern in nature
Term
 Scientific Theory
Definition
 an explanation based on numerous observations, supported by experimental results, that may explain why things may work the way they do
Term
 easurement
Definition
 a comparison between an unknown quantity and a standard
Term
 Precision
Definition
 a characteristic of a measured value describing the degree of exactness of a measurement
Term
 Accuracy
Definition
 a characteristic of a measured value that describes how well the results of a measurement agree with the "real" value, which is the accepted value, as measured by competent experiments
Term
 Independent variable
Definition
 the factor that is changed or manipulated during an experiment
Term
 Dependent variable
Definition
 the factor in an experiment that depends on the independent variable
Term
 line of best fit
Definition
 a line that best passes through or near graphed data; used to describe data and predict where new data will appear on the graph
Term
 linear relationship
Definition
 a type of relationship that exists between two variables whose graphed data points lie on a straight line
Term
Definition
 a parabolic relationship that results when one variable depends on the square of another variable
Term
 Inverse relationship
Definition
 a hyperbolic relationship that results when one variable depends on the inverse of another variable
Term
 Motion diagram
Definition
 a series of images showing the positions of a moving objects taken at regular (equal) time intervals
Term
 Particle Model
Definition
 a simplified version of a motion diagram in which the moving object is replaced by a series of single points
Term
 Coordinate system
Definition
 a system used to describe motion that gives the zero point location of the variable being studied and the direction in which the values of the variable increase
Term
 origin
Definition
 the point at which both variables in a coordinate system have the value zero
Term
 position
Definition
 the separation between an object and the origin; it can be either positive or negative
Term
 distance
Definition
 a scalar quantity that describes how far an object is from the origin
Term
 magnitude
Definition
 a measure of size
Term
 vectors
Definition
 quantities, such as position, that have both magnitude and direction
Term
 scalars
Definition
 quantities, such as temperature or distance, that are just numbers without any direction
Term
 resultant
Definition
 a vector that results from the sum of two other vectors; it always points from the first vector’s tail to the last vecto's tip
Term
 time interval
Definition
 the difference between two times; final time- initial time
Term
 displacement
Definition
 a change in position having both magnitude and direction; is equal to the final position minus the initial position
Term
 position time graph
Definition
 a graph that can be used to determine an object’s velocity and position, as well as where and when two objects meet, by plotting the time data on the x-axis and the position data on the y-axis
Term
 instantaneous position
Definition
 the position of an object at any particular instant in time
Term
 average velocity
Definition
 the change in position, divided by the time during which the change occurred; the slope of an object's position time graph
Term
 average speed
Definition
 how fast an object is moving; is the absolute value of the slope of an object’s position-time graphcant be negative
Term
 instantaneous velocity
Definition
 a measure of motion that tells the speed and direction of an object at a specific instant in time
Term
 veloctiy-time graph
Definition
 a graph that can be used to plot the velocity of an object vs time and to determine the sign of an object's acceleration
Term
 acceleration
Definition
 the rate at which the velocity of an object changes
Term
 average acceleration
Definition
 the change in an object’s velocity during a measurable time interval, divided by that specific time interval; measured in m/s2
Term
 instantaneous acceleration
Definition
 the change in an object’s velocity at a specific instant of time
Term
 free fall
Definition
 the motion of a body when air resistance is negligible and the motion can be considered due to the force of gravity alone
Term
 acceleration due to gravity
Definition
 the acceleration of an object in free fall, resulting from the influence of Earth’s gravity; acceleration due to gravity on Earth, g, is 9.80 m/s2 toward the center of Earth
Term
 force
Definition
 a push or pull exerted on an object that causes a change in motion; vector b/c it has both direction and magnitude
Term
 free-body diagram
Definition
 a physical model that represents the forces acting on a system
Term
 net force
Definition
 the vector sum of all the forces on an object
Term
 2nd law
Definition
 states that the acceleration of an object is proportional to the net force and inversely proportional to the mass of the object being accelerated
Term
 1st law
Definition
 states that an object at rest will remain at rest, and a moving object will continue moving in a straight line with constant speed, if and only if the net force acting on that object is zero
Term
 inertia
Definition
 the tendency of an object to resist change
Term
 equilibrium
Definition
 the condition in which the net force on an object is zero
Term
 apparent weight
Definition
 the force experienced by an object, resulting from all the forces acting it, giving the object an acceleration
Term
 weightlessness
Definition
 an object's apparent weight of 0 that results when there are no control forces pushing up on the object
Term
 drag force
Definition
 the forces exerted by a fluid on an object moving through the fluid; depends on the object's motion and properties and the fluid's properties
Term
 terminal velocity
Definition
 the constant velocity of an object that is reached when the drag force equals the force of gravity
Term
 interaction pair
Definition
 a pair of forces that are equal in strength, but opposite in direction
Term
 3rd law
Definition
 states that all forces come in pairs and that the two forces in a pair act on different objects and are equal in strength and opposite in direction
Term
 tension
Definition
 the specific name for the force exerted by a rope or a string
Term
 normal force
Definition
 the perpendicular contact force exerted by a surface on another object
Term
 compoonents
Definition
 projections of the component vectors
Term
 vector resolution
Definition
 the process of breaking a vector into its components
Term
 kinetic friction
Definition
 the force exerted on one surface by a second surface when the two surfaces rub against one another because one or both of the surfaces are moving
Term
 static friction
Definition
 the force exerted on one surface by a second surface when there is no motion between the two surfaces
Term
 coefficiant of kinetic friction
Definition
 the slope of a line, mk , between two surfaces, relating frictional force to normal force
Term
 coefficient of static friction
Definition
 a dimensionless constant depending on the two surfaces in contact. It is used to calculate the maximum static frictional force that needs to be overcome before motion begins
Term
 equilibriant
Definition
 a force that places an object in equilibrium; is the same magnitude as the resultant, but opposite in direction
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