air resistance
form of friction between a moving object and the air
around it
avalanche
sudden rush of lots of snow, ice, or rocks down a mountain
compass
instrument that uses a magnetic needle to show direction
distance
amount of space between two places or objects
effort
force needed by a machine in order to act upon a load
force
push or pull that makes an object move, go faster, or
change direction
friction
force that is caused by contact between the surfaces of two
objects, and that slows down movement
fulcrum
the point around which a lever turns
gravity
force that pulls objects down towards the center of the Earth
lever
simple machine that increases force, letting you do a lot of easy
work instead of doing a little bit of hard work
load
amount of something that is moved by a machine
magnet
object or material that attracts iron and some other metals
poles
two points, such as the ends of a magnet, that have opposing
magnetic qualities
simple machine
basic piece of equipment with a system of parts that
work together
speed
how far something travels in a given amount of time
surface area
total area of an exposed surface
thrust
force that makes an object move or speed up
weight
measure of the pull of gravity on an object
GLOSSARY
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