Motion in One Dimension (Linear) The simplest form of motion Complex motion can be broken down into one-dimensional motion Motion takes place over time and depends upon a frame of reference

Displacement A change in position (xf – xi) = ∆x [units = m] Not the same as “distance” Displacement has direction The sign (positive or negative) indicates the direction within the frame of reference

Velocity Average velocity is displacement (change in position) divided by time vavg = ∆x/∆t = (xf – xi)/(tf – ti) [units = m/sec] Not the same as “speed” (which is “distance”/time) Velocity is the slope of a line/curve in a time-distance graph Instantaneous velocity is not necessarily equal to average velocity The sign (positive or negative) indicates the direction

Vectors Magnitude and direction – displacement, velocity, acceleration (oh, yeah!) Represented graphically as an arrow (from tail to tip) When two or more vectors are involved a “resultant” vector can be found by adding the individual vectors together – the new tail starts at the old tip vectors can be moved parallel to themselves vectors can be added in any order vector subtraction = the addition of an opposite vector