23 terms

# Sophie Motion

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speed
rate at which another object moves
friction
a force that causes an oject to slow down and finally stop
constant speed
speed of an object that doesn't change
force
a push or pull
horizontal
line that runs across a graph
average speed
speed of an object that changes
vertical
line that runs up and down on a graph
velocity
speed in a given direction
instantaneous speed
the speed of an object at any instant of time
accerelation
the change in velocity divided by the time needed for the change to occur
gravity
the pull that all objects exert on each other
Newton's first law of motion
an object will not change its motion unless a force acts on it
friction
a force that resists motion between two surfaces that are in contact
inertia
the tendency to resist a change in motion
Newton's 2nd law of motion
a net force acting on an object changes the motion of the object
Newton's 3rd law of motion
when one object exerts a force on a second object, the second object exerts an equal force in the opposite direction on the first object
work
when a force causes an object ot move in the same direction that the force is applied
simple machine
a machine that uses only one movement
compound machine
a combination of simple machines