work
when you exert a force on an object that causes the object to move some distance
how do you know if work is being done on an object
if an object moves in the same direction in which the force is exerted
joule
measurement for work, 1 joule is to move an object a distance of one meter
power
the rate at which work is done
a machine makes work easier by changing at least one of three factors, what are the three factors
a machine may change the amount of force you exert, the distance over which you exert your force, or in the direction in which you exert your force
machine
a device that allows you to do work in a way that is easier
input force
the force you exert on the machine
input distance
the distance the input force moves the machine
output force
the force the machine exerts on an object
output distance
the work the machine dose over another distance
input work
the input force times the input distance
output work
the output force times output distance
mechanical advantage
the number of times a machine increases a force exerted on it
efficiency
compares the output work to the input work of machine
what are the six basic types of simple machines
incline plane, wedge, screw, lever, wheel and axle, and pulley
most of the machines in your body are what?
levers that consist of bone and muscles
what is the ideal mechanical advantage of a compound machine
it is the product of the individual ideal mechanical advantages that make it up
incline plane
a flat, slope
wedge
a device that is thick at one end and tapers to a thin edge at the other end
screw
can be thought of as an incline plane wrapped around a cylinder
lever
is a ridged bar that is free to pivot or rotate on a fixed point
fulcrum
the fixed point that a lever pivots around
wheel and axle
a simple machine made out of two circular or cylindrical objects fasted together that rotate about a common axis
pulley
a simple machine made of a grooved wheel with a rope or cable rapped around it
compound machine
a machine that utilizes two or more simple machines
what are two basic types of energy
kinetic and potential
energy
the ability to do work or cause change
kinetic energy
the energy an object has due to its motion
potential energy
stored energy that results from the position or shape of an object
gravitational potential energy
potential energy related to an objects hight
elastic potential energy
the potential energy associated with objects that can be stretched or compressed
what are forms of energy that are associated with particles of an object
thermal energy, electrical, energy chemical energy nuclear energy, electromagnetic energy
mechanical energy
energy associated with the position and motion of an object
thermal energy
the total potential and kinetic energy of the particles in an object
electrical energy
the energy of electric charges
chemical energy
potential energy stored in chemical bonds that hold chemical compounds together
nuclear energy
a type of potential energy that is stored in the nucleus of an atom
electromagnetic energy
waves that have some electrical and magnetic properties
what is the most common energy transformation between
kinetic and potential
energy transformation
a change from one form of energy to another
law of conservation of energy
states that when one form of energy is transferred to another, no energy is destroyed in the process
matter
is anything that has mass and takes up space
fossil fuels contain energy that came from what?
the sun
fossil fuel can be burned to release what type of energy?
chemical energy
fossil fuel
fuels made from materials that formed hundreds of millions of years ago.
what are some examples of fossil fuel
coal, petroleum, and natural gas
combustion
the the process of burning fuels
