a push or a pull
force
a change in the position of an object
motion
a force when two objects rub together that slows the motion of an object
friction
an invisible force that pulls any object down, toward the Earth
gravity
to guess what will happen based on things you know
predict
a pretend version of something that scientists use when the real thing is too big, small, or complicated to work with
model
something that happens again and again and again in a way that can be predicted
pattern
to move an object toward you
pull
to move an object away from you
push
two equal forces that push or pull in opposite directions so that the object doesn't move
balanced forces
two forces that push and pull in opposite directions where one force is greater than the other so that the object moves
unbalanced forces
to make a plan for creating or doing something
design
a person who uses science to come up with solutions to problems
engineer
a bridge that is supported by thick poles
pillar/beam bridge
a bridge with a curved arch in the center
arch bridge
a bridge where the weight is pulled up by ropes hung from tall poles
suspension bridge
