Physical Science Vocab

how far an object moves

distance and direction of an objects change in postion from the starting point

the speed and direction of a moving object

speed of an object at a given point in time; is constant for an object moving with constant speed and changes with the time for an object that is slowing down or speeding up

speed that stays the same

a push or pull exerted on an object

resistance of an object to a change in its motion

forces on an object that combine to give a zero net force and don't change the motion of the object

an unequal force on an object

sum of the forces that are acting on an object

rate of change of velocity; can be calculated by dividing the change in the velocity by the time it takes the change to occur

property of a moving object that equals its mass times its velocity

frictional force that opposes the motion of two surfaces sliding past each other

when one object is rolling across another

when neither object is moving

force that opposes the sliding motion between two touching surfaces

force that opposes the motion of objects that move through the air

a net force that is directed toward the center of a curved or circular path

the force of attraction between all masses in the universe

any object that is propelled through space by the exertion of force

the capacity for work or vigorous activity

energy a moving object has because of its motion depends on the mass and speed of the object

energy stored by objects due to their position above Earth's surface; depends on the distance above Earth's surface and the object's mass

energy stored in chemical bonds

energy stored when an object is compressed or stretched

ratio of the output force exerted by a machine to the input force applied to the machine

transfer of energy that occurs when a force makes an object move; measured in joules

amount of work done or the amount of energy transferred divided by the time required to do the work or transfer the energy, measured in watts

device that makes doing work easier by increasing the force applied to an object, changing the direction of an applied force, or increasing the distance over which a force can be applied

machine that does work with only one movement ex. lever, pulley, wheel and axle, inclined plaine, screw and wedge

machine that is a combination of two or more simple machines

the input work equals the output work

force applied by the machine

a measure of how much of the work put into a machine is changed into useful output work by the machine

a grooved wheel with a rope, chain, or cable running along the groove

a simple machine consisting of a shaft or axle rotate together

a sloping surface such as a ramp that reduces the amount of force required to do work

an inclined plane wrapped in a spiral around a cylindrical post

an inclined plane with one or two sloping sides

a wheel and axle with the wheel having teeth around its rim

electric current used or regarded as a source of power

the accumulation of excess electric charge on an object

anything that carries or moves current

material that blocks the flow of electtric current across it

flash of light in the sky caused by an electrical discharge

device for detecting the presence and determining the sign of electric charges by means of electrostatic attraction and repulsion, often between two pieces of gold leaf enclosed in a glass-walled chamber

the net movement of electric charges in a single direction; measured in amperes

provides the voltage difference that is needed to keep current flowing in a circuit

a voltage-generating cell having an electrolyte in the form of moist paste

contains two connected plates made of different metals or metallic compounds in a conducting solution

the process of transferring charge by touching or rubbing

the rearrangement of electrons on a neutral object caused by a nearby charged object

the tendency for a material to oppose the flow of electrons changing electrical energy into thermal energy and light

the circuit has only one loop to flow through

contains two or more branches for current to move through

no curent flows through this circuit

endless path for the flow of current

contains a small metal piece that melts if the current becomes too high

contains a pice of metal that bends when the current in it is so large that it gets hot

the current in a circuit equals the voltage difference divided by the resistance; I=V/R

the rate at which electrical energy is converted to another form of energy

energy made available by the flow of electric charge through a conductor; measured in kilowatt hours

the force applied by the machine

a bar that is free to pivot or turn around a fixed point

When one object exerts a force on a second object the second one exerts a force on the first that is equal in strength and opposite in direction

the acceleration of an object is in the same direction as the net force on the object

an object at rest will remain at rest unless acted on by an unbalanced force

states that energy can never be created or destroyed

states that charge can be transferred from one object to another but can't be created or destroyed

states that momentum can be transferred from one object to another