Nature of Energy
ability to cause change
energy
energy may change form but it cannot be createdor destroyed.
law of conservation of energy
energy is measured in units called
joules
device that makes work easier
machine
machine that does work with only one movement of the machine
simple machine
energy in the form of motion
kinetic energy
total amount of kinetic energy and potential energy in a system
Mechanical energy
what has to happen for work to be done
something has to move in the same direction as the force
increasing force, increasing distance, changing direction
ways a machine makes work easier
lever, pulley, wheel & axle, inclines plane, screw, wedge
simple machines
elastic, chemical, and gravitational
types of potential energy
change in energy when eating an orange during half time of your soccer game
chemical to kinetic
force times distance
work
measure of houw much work put into a machine is changed into useful output work by the machine
efficiency
when you use a paint can opener to open a can of paint , you use the opener as a simple ____
lever
depends on the mass and velocity of object
kinetic energy
as a pendulum swings, energy is continuously transformed between kinetic energy and _______
potential energy
rate at which work is done
power
force applied to the machine
input force
which body parts act as the fulcrums of levers:
muscles, bones, joints, tendons
joints
energy change when starting a campfire
chemical PE to thermal and radiant
a newton-meter is a meter is a unit of work also known as the
joule
transfer of energy that occurs when a force makes an object move
work
ratio of output force to input force
mechanical advantage
which body parts are shaped like wedges:
muscles, tendons, incisors, bones in your leg
incisors