Physics Part 1

an object's change in position relative to a reference point
how much ground an object has covered during its motion regardless of its starting or ending position
how far out of place an object is; it is the object's overall change in position
distance equation
d = xf - xi
the distance traveled divided by the time interval during which the motion occurred
speed equation
s = d/t
the speed of an object in a particular direction
the rate at which velocity changes over time; an object accelerates if its speed, direction, or both change
acceleration equation
A = (vf - vi)/t
a push or a pull exerted on an object in order to change the motion of the object; force has size and direction
newton (N)
the SI unit for force; 1N = 1kg x 1m/s2
net force
the combination of all of the forces acting on an object
balanced forces
the forces on an object produce a net force of 0 N
unbalanced forces
the net force on an object is not 0 N
a force that opposes motion between two surfaces that are in contact
kinetic friction
friction between moving surfaces; kinetic means moving
static friction
a force is applied to an object but does not cause the object to move; static means not moving
a force of attraction between objects that is due to their masses
Law of Universal Gravitation
Part 1: Gravitational Force Increases as Mass Increases. Part 2: Gravitational Force Decreases as Distance Increases.
a measure of the gravitational force exerted on an object; its value can change with the location of the object in the universe; SI unit = Newton (N)
a measure of the amount of matter in an object; SI unit = gram (g)
Acceleration Due to Gravity
Objects fall to the ground at the same rate.
Velocity increases by 9.8 m/s per second
∆v = g x t
air resistance
the force that opposes the motion of objects through air
terminal velocity
the constant velocity of a falling object when the force of air resistance is equal and opposite to the force of gravity
free fall
the motion of a body when only the force of gravity is acting on the body
centripetal force
unbalanced force that causes objects to move in a circular path
projectile motion
the curved path that an object follows when thrown, launched, or otherwise projected near the surface of Earth
vertical motion
a motion that is perpendicular to the ground
horizontal motion
a motion that is parallel to the ground
Newton's First Law of Motion
An object at rest remains at rest, and an object in motion remains in motion at a constant speed and in a straight line unless acted on by an unbalanced force
the tendency of an object to resist a change in motion unless an outside force acts on the object
Newton's Second Law of Motion
The acceleration of an object depends on the mass of the object and the amount of force applied; F = m x a
Newton's Third Law of Motion
Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first
a quantity defined as the product of the mass and velocity of an object
momentum equation
p =m x v
Law of Conservation of Momentum
any time objects collide, the total amount of momentum stays the same
the transfer of energy to an object by using a force that causes the object to move in the direction of the force
the rate at which work is done or energy is transformed
a device that helps do work by either overcoming a force or changing the direction of the applied force
work input
the work done on a machine; the product of the input force and the distance through which the force is exerted
work output
the work done by a machine; the product of the output force and the distance through which the force is exerted
mechanical advantage
number that tells how many times a machine multiplies force
mechanical efficiency
a quantity, usually expressed as a percentage, that measures the ratio of work output to work input in a machine
a simple machine that consists of a bar that pivots at a fixed point called a fulcrum
a simple machine that consists of a wheel over which a rope, chain, or wire passes
wheel and axle
simple machine consisting of two circular objects of different sizes; the wheel is the larger of the two circular objects
inclined plane
a simple machine that is a straight, slanted surface, which facilitates the raising of loads; a ramp
simple machine that is made up of two inclined planes and that moves; often used for cutting
a simple machine that consists of an inclined plane wrapped around a cylinder
compound machine
a machine made of more than one simple machine
the capacity to do work
kinetic energy
the energy of an object that is due to the object's motion
potential energy
the energy that an object has because of the position, shape, or condition of the object
gravitational potential energy
the amount of energy that an object has depends on its weight and its height
mechanical energy
the amount of work an object can do because of the object's kinetic and potential energies
thermal energy
the kinetic energy due to random motion of the particles that make up an object
chemical energy
energy of a chemical compound that changes as its atoms are rearranged
electrical energy
the energy of moving electrons
sound energy
caused by an object's vibrations
light energy
produced by the vibrations of electrically charged particles
nuclear energy
energy that comes from changes in the nucleus of an atom
energy conversion
a change from one form of energy to another
closed system
a group of objects that transfer energy only to each other
Law of Conservation of Energy
the law that states that energy cannot be created or destroyed but can be changed from one form to another
a non-solid state of matter in which the atoms or molecules are free to move past each other, as in a gas or liquid
the amount of force exerted per unit area of a surface
the SI unit of pressure (symbol, Pa);
1 Pa =1 N/m2
atmospheric pressure
the pressure caused by the weight of the atmosphere
buoyant force
the upward force that keeps an object immersed in or floating on a liquid
Archimedes' principle
the buoyant force on an object in a fluid is an upward force equal to the weight of the fluid that the object takes the place of, or displaces
Bernoulli's principle
as the speed of a moving fluid increases, the fluid's pressure decreases
the pushing or pulling force exerted by the engine of an aircraft or rocket
an upward force on an object that moves in a fluid
a force parallel to the velocity of the flow; it opposes the direction of an aircraft and, in combination with thrust, determines the speed of the aircraft
Pascal's Principle
a change in pressure at any point in an enclosed fluid will be transmitted equally to all parts of that fluid
a measure of how hot (or cold) something is; specifically, a measure of the average kinetic energy of the particles in an object
thermal expansion
an increase in the size of a substance in response to an increase in the temperature of the substance
absolute zero
the temperature at which molecular energy is at a minimum (0 K on the Kelvin scale or
-273.15 °C on the Celsius scale)
the energy transferred between objects that are at different temperatures
thermal equilibrium
the point at which two object that are touching reach the same temperature
the transfer of energy as heat through a material
thermal conductor
a material through which energy can be transferred as heat
thermal insulator
a material that reduces or prevents the transfer of heat
the movement of matter due to differences in density; the transfer of energy due to the movement of matter
the transfer of energy as electromagnetic waves
states of matter
the physical forms of matter, which include solid, liquid, and gas
change of state
the change of a substance from one physical state to anothe

Flickr Creative Commons Images

Some images used in this set are licensed under the Creative Commons through
Click to see the original works with their full license.