28 terms

# Chapter 5 and 9

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friction
force that opposes motion between surfaces that are touching
kinetic
energy of motion
potential
energy of position, if you lift an object you give it gravitational potential energy
motion
change in position of an object related to a reference point
reference point
an object that appears to stay in place
mechanical
energy that is the sum of kinetic and potential
elastic
type of potential energy where the object is stored in something elastic: rubber band, wind-up toy, spring, bow string
energy conversion
change from one form of energy to another
balanced
type of forces that are equal (net force = 0), a balanced force does not get an object to start moving or to stop/change direction
unbalanced
where the net forces are not equal (not = 0), an unbalance force will cause an object to start, stop, or change direction
weight
how much gravity is pulling on an object
speed
distance divided by time (s = d / t)
newton
unit used to express force
sliding
kinetic friction where the object slides, often this friction is more than rolling friction (brakes, sliding a book, push box across the floor)
rolling
kinetic friction where the object rolls, often this friction is less than sliding friction (wheels, ball-bearing, etc.)
mass
the amount of matter in an object
force
a push or a pull ON AN OBJECT
velocity
a speed, but in a particular direction (like N, S, E, W)
energy
ability to do work
photosynthesis
type of chemical change that lets plants change light energy into chemical energy
nuclear
type of energy where the nucleus of an atom splits or changes
light
type of energy that is vibrations of electrically charged particles (vibrating electrical waves)
sound
type of energy from vibrating objects that transmit vibrations through the air (vibrating air particles)
electrical
energy of moving electrons (the flow of electrons)
thermal
random motion of particle that make up an object (also called heat energy) we measure it often with temperature/THERMometer
chemical
type of energy where a compound releases energy when its atoms/molecules are re-arranged (digesting food is a good example)
perpetual motion
machine that would go on forever without ever adding any energy to it (this type of machine is not possible)
static friction
friction that is not moving....Thank you Allie H!