Kinematics 1-D Motion

Mechanics The study of the motion of objects Kinematics Mechanics The study of the motion of objects Kinematics – the science of describing the motion of objects using words, diagrams, numbers, graphs, and equations

Scalars vs. Vectors Kinematics Scalars Quantities that are fully described by a magnitude alone Ex. Speed, distance Vectors Quantities that are fully described by both a magnitude and a direction Ex. Velocity, displacement, acceleration

Distance vs. Displacement Kinematics Distance vs. Displacement Distance Scalar Quantity How much ground an object has covered (path taken) Displacement Vector Quantity How far out of place an object is (i.e. overall change in position)

What’s the distance? What’s the displacement? Kinematics What’s the distance? What’s the displacement?

Speed vs. Velocity ∆ Distance ∆ Time Displacement Time Kinematics Scalar Quantity How fast an object is moving Average Speed = Velocity Vector Quantity The rate at which an object changes its position (i.e. speed with a direction) Average Velocity = ∆ Distance ∆ Time Displacement Time

Average vs. Instantaneous Kinematics Average vs. Instantaneous Average The average of all the instantaneous measurements Average Speed = Instantaneous The measurement at any given time Instantaneous Speed = ∆Distance ∆Time Distance Time

Acceleration Vector Quantity (magnitude & direction) Kinematics Acceleration Vector Quantity (magnitude & direction) The rate at which an object changes its velocity This does not mean if an object is going fast but rather if it is speeding up, slowing down, or changing direction Average Acceleration = ∆Velocity Time

Kinematics Acceleration

Position vs. Time Velocity vs. Time Kinematic Graphs Position vs. Time Velocity vs. Time

Position vs. Time Graphs Kinematics Position vs. Time Graphs Slope = Velocity Straight line = Constant Velocity, No acceleration Curved line = Changing Velocity, Accelerating Horizontal (Flat) line = Not moving, velocity is 0 m/s

Position vs. Time Graphs Kinematics Position vs. Time Graphs

Velocity vs. Time Graphs Kinematics Velocity vs. Time Graphs Slope = Acceleration Straight line = Constant acceleration Upward sloping line = positive acceleration Downward sloping line = negative acceleration Horizontal (Flat) Line = Constant velocity, acceleration is 0 m/s2

Velocity vs. Time Graphs Kinematics Velocity vs. Time Graphs

Kinematics Kinematics Graphs

Kinematics Kinematics Graphs p (m) v (m/s) a (m/s2)

Kinematics Free Fall Any object that is being acted upon only by the force of gravity is said to be in a state of free fall. Always assume no air resistance, unless told otherwise Acceleration due to gravity (g) = 9.8 m/s2 downward ΔVf = gt d = ½gt2