# Vocabulary - Lena - Purvis' Science Spot ```Physics Vocabulary
By Lena Hodge
Introduction
Chapters 1-7
Vocabulary and their
meanings.
All vocabulary for chapters
 Models, System, hypothesis, controlled experiment,
accuracy, precision, significant figures
 Frame of reference, displacement, average velocity,
instantaneous velocity, acceleration, free fall
 Scalar, vector, resultant, components of a vector,
projectile motion
 Force, inertia, net force, equilibrium, weight, normal
force, static friction, kinetic friction, coefficient of friction
Continued….
 Work, kinetic energy, work-kinetic energy theorem,
potential energy, gravitational potential energy, elastic
potential energy, spring constant, mechanical energy,
power
 Momentum, impulse, perfectly inelastic collision, elastic
collision
 Centripetal acceleration, gravitational force, torque,
lever arm
Chapter 1
 Model- a pattern, plan, representation, or description
designed to show the structure or workings of an
object, system, or concept.
 System- a set of particles or interacting components
considered to be a distinct physical entity for the
purpose of study.
 Hypothesis-an explanation that is based on prior
scientific research or observations one that can be
tested
Chapter 1 continued..
 Controlled experiment- an experiment that tests only
one factor at a time by comparing a control group with
an experimental group.
 Accuracy- a description of how close a measurement
is to the correct or accepted value of the quantity
measured.
 Precision- the degree of exactness of a measurement
Chapter 1 continued..
 Significant figures- those digits in a measurement that
are known with certainty plus the first digit that is
uncertain
Chapter 2
 Frame of reference- a system for specifying the
precise location of objects in space and time
 Displacement- the change in position of an object
 Average velocity- the total displacement divided by
the time interval during which the displacement
occurred
 Instantaneous velocity- the velocity of an object at
some instant or at a specific point in the object’s path
Chapter 2 Continued..
 Acceleration- the rate at which velocity changes over
time; an object accelerates if its speed, its direction, or
both change.
 Free fall- the motion of a body when only the force due
to gravity is acting on the body
Chapter 3
 Scalar- a physical quantity that has magnitude but no
direction
 Vector- a physical quantity that has both magnitude
and direction
 Resultant- a vector that represents the sum of two or
more vectors
 Components of a vector- the projections of a vector
along the axes of a coordinate system
Chapter 3 Continue..
 Projectile motion- the motion that an object exhibits
when thrown, launched, or otherwise projected near
the surface of Earth
Chapter 4
 Force- an action exerted on an object that may change
the object’s state of rest or motion
 Inertia- the tendency of an object to resist being moved
or, if the object is moving, to resist a change in speed or
direction
 Net force- a single force whose external effects on a rigid
body are the same as the effects of several actual forces
acting on the body
 Equilibrium- the state in which the net force on an object
is zero
Chapter 4 continued..
 Weight- a measure of the gravitational force exerted on an
object; its value can change with the location of the object in
the universe
 Normal force- a force that acts on an object lying on a
surface, acting in a direction perpendicular to the surface
 Static friction- the force that resists the initiation of sliding
motion between two surfaces that are in contact and at rest
Chapter 4 continued..
 Kinetic friction- the force that opposes the movement
of two surfaces that are in contact and are sliding over
each other
 Coefficient of friction- the ratio of the magnitude of
the force of friction between two objects in contact to
the magnitude of the normal force with which the
objects press against each other
Chapter 5
 Work- the product of the component of a force along
the direction of displacement and the magnitude of the
displacement
 Kinetic energy- the energy of an object that is
associated with the object’s motion
 Work–kinetic energy theorem- the net work done by all
the forces acting on an object is equal to the change in
the object’s kinetic energy
Chapter 5 continued..
 Potential energy- the energy associated with an object
because of its interaction with the environment
 Gravitational potential energy- the potential energy
associated with an object’s position relative to a
gravitational source
 Elastic potential energy- the energy stored in any
deformed elastic object, such as a compressed spring
or stretched rubber band
Chapter 5 continued..
 Spring constant- a parameter that is a measure of a
spring’s resistance to being compressed or stretched
 Mechanical energy- the sum of kinetic energy and all
forms of potential energy
 Power- a quantity that measures the rate at which work
is done or the rate of energy transfer by any method
Chapter 6
 Momentum- a vector quantity defined as the product of
the mass and velocity of an object
 Impulse- the product of the force and the time interval
over which the force acts on an object
 Perfectly inelastic collision- a collision in which two
objects stick together after colliding
 Elastic collision-a collision in which the total
momentum and the total kinetic energy are conserved
Chapter 7
 Centripetal acceleration- the acceleration directed
toward the center of a circular path
 Gravitational force- the mutual force of attraction
between particles of matter
 Torque- a quantity that measures the ability of a force
to rotate an object around some axis
 Lever arm- the perpendicular distance from the axis of
rotation to a line drawn along the direction of the force
Conclusion
To sum it all up you
have just learned all the
vocabulary you will need
to know for chapters 17.
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