Motion in One Dimension Kinematics

Dynamics vs. Kinematics Dynamics – motion related to __________ Kinematics – describes motion ______________ without regard to cause or force

Frame of Reference Specify an ______ For 1-D motion the coordinate system is ______ x = 0 x

Time and Space Instant ≡ particular ______ in time Interval ≡ ________ between two instants Position ≡ particular ______ in space Displacement ≡ __________ between two positions

Vectors vs. Scalars Vectors – indicate magnitude and ______ Boldfaced and/or vector sign Displacement Velocity Acceleration Scalars – indicate __________ only Distance Speed Magnitude of acceleration

Displacement is a Vector Fig. 2.2, p. 25 For 1-D, vector nature is indicated by ______sign

Displacement Change in _________ is called displacement The sign tells us if displacement is towards _______ or ________ values

Average Velocity Displacement divided by _____ interval The ____ tells us if object is moving toward positive or negative values

Instantaneous Velocity The average velocity when the time interval approaches _____ It is the ______ of the line of a position versus time graph

Instantaneous Velocity – Graphical Interpretation What is v at t = 4 s?

Average Acceleration The change in velocity over a _______________

Instantaneous Acceleration The average acceleration when the time interval approaches _____ It is the ______ of a velocity versus time graph

Signs of v and a v a Object is: + speeding up – slowing down

Graphical Interpretation Red Blue Green Rank the velocities in decreasing order. Find numerical values for the velocities. Rank the speeds in decreasing order.

Graphical Interpretation (cont’d) Red Green Are the velocities constant? Which has the larger acceleration?

Types of Motion Uniform Motion: v = ________, a = ______ Nonuniform Motion Uniform acceleration: a = _________ Nonuniform acceleration: a is _____ constant