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  For each section (A, B, C, & D)of the graph, describe the motion of the object.

A

B

C

DKinematics in One Dimension

  Differentiate between displacement and distance   Calculate average velocity   Construct and interpret position-time graphs   Describe motion in terms of a changing velocity

(acceleration).   Construct and interpret velocity vs. time graphs.   Use kinematic equations to calculate displacement,

time, and velocity under constant accelerations   Construct and interpret acceleration vs. time graphs.   Understand how constant acceleration relates to objects

in free fall.   Calculate displacement, velocity, and time at various

points in the motion of a freely falling body.

  Frame of reference   Method of specifying location   Any is valid   Chosen for convenience and simplicity

  One dimensional   Two dimensional   Three dimensional

  Distance and direction from initial position to final position

  Positive or Negative denotes direction

West East

South North

Down Up

Left Right

Backward Forward

Negative Positive

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  200 m East and 300 m East   Distance= _____ Displacement=_______

  200 m East and 300 m West   Distance= _____ Displacement=_______

  200 m East and 200 m West   Distance= _____ Displacement=_______

  Differentiate between displacement and distance   Calculate average velocity   Construct and interpret position-time graphs   Describe motion in terms of a changing velocity

(acceleration).   Construct and interpret velocity vs. time graphs.   Use kinematic equations to calculate displacement,

time, and velocity under constant accelerations   Construct and interpret acceleration vs. time graphs.   Understand how constant acceleration relates to objects

in free fall.   Calculate displacement, velocity, and time at various

points in the motion of a freely falling body.

  Positive or negative

•  Displacement divided by the time interval   Speed does not include a direction

  Based on distance

  Velocity includes a direction   Based on displacement

  A car travels east 200 km and then to the west 200 km. The entire trip lasts 4 hrs.   What was the car’s average speed?

  What was the car’s average velocity?

Average Speed =

Average Velocity =

  Differentiate between displacement and distance   Calculate average velocity   Construct and interpret position-time graphs   Describe motion in terms of a changing velocity

(acceleration).   Construct and interpret velocity vs. time graphs.   Use kinematic equations to calculate displacement,

time, and velocity under constant accelerations   Construct and interpret acceleration vs. time graphs.   Understand how constant acceleration relates to objects

in free fall.   Calculate displacement, velocity, and time at various

points in the motion of a freely falling body.

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  Time on x-axis

  Position on y-axis

• Slope =

A

B

C

D

  May not be the same as average velocity

•  The slope of the tangent line to any point on the graph

  Using the graph, describe the object’s motion in each section of the graph.

  Rate of change of velocity   Occurs when speed or direction changes

•  m/s2

  Has direction and magnitude

Decreasing"Backward"Increasing"Backward"Decreasing"Forward"Increasing"Forward"

Acceleration"Speed change"

Motion Direction"

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  Velocity on y-axis

  Time on x-axis

•  Slope is the

  Instantaneous Acceleration

  Slope of the graph at any certain point

  Can be found by drawing a tangent line

  Displacement –  The area under the curve

–  May need to be found in parts

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1.  For each graph below, what would the motion be for a pos-time graph?

2.  For each graph below, what would the motion be for a vel-time graph?

(0,0) (0,0)

  Acceleration on y-axis

  Time on x-axis

  Change in Velocity

  Area under the curve

  May need to be done in parts

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  Differentiate between displacement and distance   Calculate average velocity   Construct and interpret position-time graphs   Describe motion in terms of a changing velocity

(acceleration).   Construct and interpret velocity vs. time graphs.   Use kinematic equations to calculate displacement,

time, and velocity under constant accelerations   Construct and interpret acceleration vs. time graphs.   Understand how constant acceleration relates to objects

in free fall   Calculate displacement, velocity, and time at various

points in the motion of a freely falling body

  Also called uniform acceleration

  Equations only work for constant acceleration

  Vi = 0 if object starts at rest

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  The length of the barrel of a primitive blowgun is 1.20 m. Upon leaving the barrel, a dart has a speed of 14.0 m/s. Assuming that the dart is uniformly accelerated, how long does it take for the dart to travel the length of the barrel?

  A drag racer, starting from rest, speeds up for 402 m with an acceleration of 17.0m/s2. A parachute then opens, providing the car with an acceleration of 6.10m/s2. How fast is the racer moving 350.0 m after the parachute opens?

  The old world record for a car’s acceleration was from rest to 96km/hr in 3.07 seconds. How far did the car travel?

  Sketch the pos-time, vel-time, and acc-time graphs for a cannonball that is shot straight up.

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  Objects all fall at the same rate   Ignoring air resistance   Demonstrated in a vacuum or on the moon   Objects are accelerated downward at a constant rate

  Objects that go up; must come down   Up => objects are slowing down   Down => objects are speeding up

  At the top => v = 0m/s, but a ≠ 0m/s2   Object experiences a constant negative

acceleration

  Equations for constant acceleration apply to free fall

  a = g = -9.81 m/s2

  A base ball is hit straight upward at a velocity of 8.2 m/s. If the ball started 1.0m above the ground, how long before it hits the ground?

  A base ball is hit straight upward at a velocity of 8.2 m/s. If the ball started 1.0m above the ground, how long before it hits the ground?

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