Kinematics (Part 1)

doutfanaticalMechanics

Nov 14, 2013 (3 years and 9 months ago)

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Kinematics (Part 1)

What is kinematics?

Kinematics = the study of motion & how to describe it.


Motion = a change in position

Can be…


straight circular


arced back&forth




How to detect / display motion


Motion Diagram


series of images of a moving
object that records position at equal time intervals





Motion is observed based on a motionless object


Can show objects at rest, constant speed, speeding
up or slowing down



How to detect / display motion (cont.)


How can you show objects at rest, constant speed,
speeding up or slowing down?


Particle diagram


shows same thing, easier to draw


At rest (no motion) •


Constant speed (distance stays the same)

• • • • •


Speeding up (distance increases)
















Slowing down (distance decreases)

• • • • •


Motion based on Frame of Reference


Motion can / will appear to be different based on
your “Frame of Reference” (f.o.r.)


F.O.R.


one’s point of view

Ex. #1 Motion of the planet Mars (f.o.r. = Earth)








Ex. #2 Motion of the planet Mars (f.o.r. = Sun)

How to describe motion


Once you decide where / when to measure a position
change, you must set up a coordinate system.


Coordinate systems tell you the
origin,

magnitude

and
direction

of the motion. (We’ll discuss further
later)


Origin = zero point


Scalar quantity


describes magnitude (represented
with a letter, Ex. s, m,
°
C)


Vector quantity


describes magnitude and direction
(represented with a letter and arrow, Ex. v )