Motion in 1 DimensionPhysics: Chapter 2-1
Pages 40-47
Displacement Displacement- length of the straight line
drawn from initial position to final position.
Change in position of an object
Measured in meters (or km, cm, etc.)
Displacement
Displacement ≠ distance traveled
DisplacementCoordinate systems used to describe
motion (x, y, z)
xi = initial position
xf = final position
Horizontal = x-axis (Δx) Vertical = y-axis (Δy)
DisplacementDisplacement = change in position = final position – initial position
Δx = change (delta) in x-axis
∆x = xf – xi
Δy = yf – yi
DisplacementA point of reference is arbitrarily chosen,
but the same point must be used through the problem
Displacement can be positive or negative
* has magnitude & direction (+ or -) for consistency to right to left
VelocityVelocity – change in displacement during
a given time interval in a certain direction
Measured in meters per second (m/s)
Velocity Average velocity = change in position = displacement change interval time interval
V avg = Δx = Xf – Xi
Δ t tf – ti
VelocityVelocity ≠ speed Velocity has magnitude & directionSpeed has magnitude, no direction
Graphing Velocity Velocity can be
interpreted graphically
Displacement is measured over time at specific intervals
When points plotted on a graph, the
slope = average velocity
Graphing VelocitySlope = rise = change in vertical coordinate run change in horizontal coordinates
V avg = Δx = Xf – Xi
Δ t tf – ti
Graphing VelocitySteeper slope = larger velocityHorizontal slope = no velocity (object
at rest)