Motion in 1 Dimension Physics Chapter 2 1

Motion in 1 Dimension Physics: Chapter 2 -1 Pages 40 -47

Displacement l Displacement- length of the straight line drawn from initial position to final position. l Change in position of an object l Measured in meters (or km, cm, etc. )

Displacement l Displacement ≠ distance traveled

Displacement l Coordinate systems used to describe motion (x, y, z) xi = initial position xf = final position Horizontal = x-axis (Δx) Vertical = y-axis (Δy)

Displacement l Displacement = change in position = final position – initial position Δx = change (delta) in x-axis ∆x = xf – xi Δy = yf – yi

Displacement l A point of reference is arbitrarily chosen, but the same point must be used through the problem l Displacement can be positive or negative * has magnitude & direction (+ or -) for consistency to right to left

Velocity l Velocity – change in displacement during a given time interval in a certain direction Measured in meters per second (m/s)

Velocity l Average velocity = change in position = displacement change interval time interval V avg = Δx = Xf – Xi Δt t f – ti

Velocity ≠ speed l Velocity has magnitude & direction l Speed has magnitude, no direction l

Graphing Velocity l l l Velocity can be interpreted graphically Displacement is measured over time at specific intervals When points plotted on a graph, the slope = average velocity

Graphing Velocity l Slope = rise = change in vertical coordinate run change in horizontal coordinates V avg = Δx = Xf – Xi Δt t f – ti

Graphing Velocity Steeper slope = larger velocity l Horizontal slope = no velocity (object at rest) l