Force & Motion - Moody High School

filercaliforniaMechanics

Nov 14, 2013 (4 years and 1 month ago)

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Motion occurs when an object changes
position


Relative motion

motion that is not obvious


If sitting in desk, not moving relative to the desk
or school; but are moving relative to the other
planets & Sun


Unbalanced forces cause changes in motion


Relative to frame of reference

DISTANCE


How far something has
traveled


Scalar Quantity

described
by magnitude (numerical
value); 10m


Distance standard unit = m

DISPLACEMENT


Distance & direction of an
object’s change in position
from the starting point


Vector Quantity

both
magnitude & direction; 10
m, East

4m X 2m






Distance?

Displacement?

SPEED


How long it takes to go a
certain distance


Standard Unit

m/s


On a graph, slope is equal
to speed


Speed (velocity) =


distance / time



v=d/t


ACCELERATION


How long it takes to go
from being at 1 speed to
another


Standard Unit

m/s
2


Acceleration = final velocity


Initial Velocity/time


a =
v
f



v
i
/time

SPEED


Distance and object travels
per unit of time


Speed = distance/time

VELOCITY


Speed & direction of a
moving object


S = d/t or V= d/t


Standard Unit


m/s


Speed = distance/time


Product of an object’s mass & velocity


Momentum = Mass x Velocity or p = m x v


Standard units


kg x m/s


Mass & velocity together represent the force
needed to stop an object in motion


Force is needed to start & stop an object’s motion



Work is the transfer of energy when applied
force makes an object move in the direction
of the applied force


Formula


work = force x distance


Standard units


Work = joule (J)

Force = Newton (N)

Distance =
meter (m)


Power is the amount of work done in a certain
amount of time


Formula


Power = work/time or P = W/t


Standard units


Power = Watt (W)

Time = Second


An object will remain at rest, or continue to
move at a constant velocity (speed) unless a
net force acts on it


Net force on an object is equal to its mass
times its acceleration


For every force acting on an object, the
object will exert an equal, yet opposite, force


For every action there is an equal & opposite
reaction

ie
. rocket