Unit 1: One Dimensional Motion

Lesson 2 - Distance, displacement, and coordinate systems:

  • Key Terms:
[[Word[[[[Defination[[
Coordinate SystemsDefines position and direction for positive and negative number
PositionLocation of an object relative to originSymbol “x“ refer to postion
DisplacementChnage in position of an object /\ x for displacement/\ = change
DistanceTotale amount the object has moved Always a non-negative numberA scalar quantity with unit of distance
Reference FramePoint of view from which measurement can be made All frames of references are equally valid
  • Equations
<<Formula<<<<Symbol Meaning<<
/\x = x(f) - x(i)/\x = displacementx(f) = final positionx(i) = inital position

Diagram of Displacement

Lesson 3 - Average Velocity and Speed:

  • Equation
<<Formula<<<<Defination of Symbols<<
  • Key Points:
    • Avg. speed doesn ot equal the magnitude of avg. velocity
    • Speed is a scalar quantity, and avg. velocity is a vector quantity
    • Avg. velocity = direction and can be negative number when displacement is in negative direction
    • Avg. speed ~~=~~ direction; can only be positive or zero

Lesson 4 - Velocity and speed from graph

  • Key Terms
Instantaneous VelocityVelocity at a given moment in timeSI units = m/s
Instantaneous SpeedSpeed at a given moment in time Equal to the megnitude of the Intantaneous VelocitySI unites = m/s
  • Equations
<<Formula<<<<Defination of Symbols<<

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Lesson 5 - Average and instantaneous acceleration

  • What is velocity vs. time graph?
    • Veritical axis represents the velocity of the object
  • What does the slope represent on a velocity graph?
    • Slope = acceleration of the object
    • rise/run = v2-v1/t2-t1 = /\v / /\t
  • What does the aera under a velocity graph represent?
    • area under curve represent = displacement of object
    • /\x = v/\t

\

  • Key Terms
<<Words<<<<Defination<<
Avg. AccelerationRate at which velocity changes over a specified time intervalSI = m/s^2Vector Quantity
Instantaneous accelerationRate at which velocity changes at a speific intant at time SI = m/s^2Vector Quantity
  • Equation
<<Formula<<<<Symbol Defination<<

\
Lesson 6 - Motion with constant Acceleration

  • Key Terms
<<Word<<<<Defination<<
Kinematic VariableVariable that describes the moition of an object over time Includes displacement “/\X”time interval “t”intial velocity “Vi”final velocity “Vf”acceleration “a”
Kinematic Formulaformula that describe the relationships between Kinematic variable when accelaration is constant
  • Equations
<<Formula<<
  • Symbols

  • Assumptions

    • Acceleration is constant over the time interval
  • When using kinematic formulas

    • Choosing best kinematic formulas
    • figure out which variable you are not given & asked to find
    • Finsing the known variable
    • Somtimes a known variable will not be explicity given in a problem, but neither implied with codeword
      • “start from rest“ = Vi = 0
      • “dropped“ = Vi = 0
      • “Comes to a stop” = Vf = 0
    • g = 9.8 m/s^2 = acceleration due to gravity on all objects in free fall on Earth

Lesson 7 - Objects in freefall

  • Key terms:
<<Word<<<<Definition<<
Acceleration due of gravityIn the absence of air resistance, all objects fall with constant acceleration “g“ toward the surface of the Earth. On the surface of Earth, defined ad g = 9.8 m/s^2
  • Annalyzing motion for objects in freefall

    • special cade with constant acceleration
    • Accelaration due to gravity is always constant and downward
    • True even when object thrown upward or has zero velocity
  • Example

    • A ball thrown up in the air
    • Ball’s velocity is initally upwards
    • Gravity pulls ball towards earth surface with constant acceleration ““g“
    • Magnitude of velocity decreases as ball approches maxximum height
    • At highest point
    • Ball velocity is zero
    • Magnitude of the ball increases again as it falls back to the earth surface