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 )