100 terms

Physics Key terms

Hewitt textbook
the rate at which velocity changes
average speed
total distance covered divided by time interval
elapsed time
time that has passed since the beginning of a fall
free fall
when gravity is the only force on a falling object
instantaneous speed
the speed at any instant
a quantity divided by time
everything is _____ to something when discussing speed
how fast something is moving
speed and direction
when an object is at rest and the net force is zero
a push or pull
force that acts between two materials that touch as they move past each other
the unit of measurement of mass
law of inertia
every object continues in a state of rest, or of motion in a straight line at a constant speed, unless it is compelled to change that state by forces acting on it
the quantity of matter in an object
net force
the combination of all forces acting on an object
the unit of force
Newton's first law
the law of inertia
normal force
the force that balances the force of gravity to keep an object still
support force
aka normal force
the force of gravity on an object
air resistance
the friction acting on something moving through air
friction in liquids or gasses
free-body diagram
a diagram showing all the forces acting on the object
two values change in opposite directions
Newton's second law
The acceleration produced by the net force on an object is directly proportional to the magnitude of the net force, in the same direction as the net force, and is inversely proportional to the mass of the object (a= F/m)
terminal speed
when the air resistance on an object equals the weight of that object
terminal velocity
when the air resistance on an object equals the weight of that object in terms of direction
action force
one force that acts on a object
a force is part of an...
Newton's third law
whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first object
reaction force
anther force that acts on an object
when a quantity in physic does not change, specifically momentum
elastic collision
(bouncy) when objects collide and bounce away from each other
change in momentum force times time interval
inelastic collision
(sticky) when colliding objects become tangled or coupled together
law of conservation of momentum
in the absence of an external force, the momentum of a system remains the same
mass times velocity, or inertia in motion
useful work output over total work input, AMA over TMA
the ability to do work
the pivot point of the lever
the unit of measurement of work
kinetic energy
the energy due to the movement of something
law of conservation of energy
energy cannot be created or destroyed, it can only be transformed from on form into another, but the total amount of energy never changes
a simple machine that gives a mechanical advantage when given a fulcrum
a device that changes the direction of or amplifies forces
mechanical advantage
the ratio of output force to input force
mechanical energy
the energy due to the position or movement of something
potential energy
the energy due to the position of something
work done divided by the time interval, the rate at which work is done, change in energy
a kind of lever that changes the direction of a force
joule per second, unit of measurement of power
force times distance, the application of a force and the movement done by that force
work-energy theorem
The work done on an object equals the change in kinetic energy of the object
law of universal gravitation
Newton's law that states that all objects in the universe attract each other by the force of gravity
universal gravitational constant, G
the constant G in the equation for Newton's law of universal gravitation; measures the strength of gravity
fundamental electrical property explaining the mutual attractions or repulsions between electrons or protons.
a material that easily moves electrons
conservation of charge
the law that states that charges are neither created nor destroyed but only transferred from one material to another
the unit of measurement of charge
Coulomb's law
F=kq1q2/dsquared, The force between two charges particles is inversely proportional to the square of the distance between them.
electrical force
a force that one charge exerts on another
electrically polarized
when one side of an atom or molecule is induced to be slightly more positive or negative
electricity at rest
when charge is redistributed on an object because of the presence of a charged object nearby.
the process of moving charge without direct physical contact
a material that does not easily move electrons
materials that can sometimes behave as conductors or insulators
materials that can attain infinite conductivity
electric field
the space around every electrical charge
electric potential
electric potential energy per charge
electrical potential energy
energy charge posses by its location
the unit of measurement of voltage/ electric potential
electric potential
alternating current
electrons in the circuit that first flow in one direction nd then the other
the unit of measurement of current
direct current
an electric current that flows in one direction steadily
electric current
the floe of electric charge
electric power
the rate at which electrical energy is converted to into another form such as, mechanical energy, heat, or light
electric resistance
the resistance that the current offers to the flow of charge
the unit of electric resistance
Ohm's law
current is equal to voltage divided by resistance
potential difference
the difference in potential (voltage) so that charge can flow
voltage source
something that provides a potential difference
an electrical device that provides a path for electrical current to flow
in parallel
when electrical devices are connected to form branches with multiple paths for the electrons to flow
in series
when electrical devices are connected in a single pathway with one path for the electrons to flow
parallel circuit
circuit in which electric current can follow more than one path
series circuit
circuit in which electric current follows only one path
a current-carrying coil of wire with many loops
magnetic domain
clusters of aligned atoms that magnetize irons
magnetic field
the space around a magnet, in which a magnetic force is exerted
magnetic pole
the ends of a magnet where the magnetism is concentrated, they produce magnetic forces (like forces repel, and opposite forces attract)
electromagnetic induction
The phenomenon of inducing voltage voltage by changing the magnetic field around a conductor
Faraday's law
The induced voltage in a coil is proportional to the product of the number of loops and the rate at which the magnetic field changes within those loops.
a device that converts mechanical energy into electric energy
a device that increases or decreases the voltage of alternating current
a device that converts electric energy into mechanical energy
a sensitive current-indicating instrument