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In this lecture on 1D motion, we explore essential physics concepts such as displacement, velocity, and acceleration. We differentiate between displacement and distance, emphasizing that displacement includes both magnitude and direction, while distance only accounts for magnitude. We also delve into the definitions and calculations for velocity and acceleration. Students will learn to apply kinematic equations to solve various motion problems, including scenarios involving constant acceleration and free fall. Additional topics include homework assignments and lab partnerships.
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PHYS16 – Lecture 4 Physics of 1D Motion September 15, 2010
Agenda • Administration • Key Concepts – Physics 1D motion • Displacement, Velocity, & Acceleration
Administration • Clickers, Textbook, Connect • Math Exam • Look at messages • Due Sunday • Homework Assignments • Lab homework due today • Written homework due Friday • 2.38 – displacement not distance • Labs – Partners…
Key Concepts: Physics 1D Motion • Displacement, Velocity, & Acceleration • Know the definitions of these terms • Know how they are related • Motion with Constant Acceleration • Solve for constant accel. get Kinematic Eqs. • Use the Kinematic Eqs. to solve problems • Race Car • Free Fall
Displacement • Displacement vs. Distance • Displacement = final position – initial position with both magnitude and direction • Distance = total position traversed from final position to initial position, just magnitude
Velocity • Velocity vs. Speed • Velocity – final position minus initial position divided by time, both magnitude and direction • Speed – how fast you are going, just magnitude 60 mph
Acceleration • Acceleration • Final velocity minus initial velocity divided by time, both a magnitude and a direction • How much an object speeds up or slows down Position graph where acceleration is not 0 http://physics247. com
Questions: A=Yes, B=No • Can displacement be zero and distance be positive? (Yes) • Can distance ever be negative? (No) • Can speed ever be negative? (No) • Can acceleration be negative? (Yes) • Can an object that is stopped at t=0 have an acceleration? (Yes) • If an object is traveling at a constant velocity can it have an acceleration? (No)
Demo: Remote Control Car http://familycourtchronicles.com
Demo: Remote Control Car • Draw the position vs. time, velocity vs. time, and acceleration vs. time graph for each situation • Constant velocity • Constant velocity forward then constant velocity backward • Constant acceleration
Determine v • x=3t2 +4t -5 • v=6t+4 • a=4t2+3t+5 • v=(4/3)t3+(3/2)t2+5t+v0 • laksdj
Summary • Displacement vs. Distance • Velocity vs. Speed • Acceleration • Know how to interconvert between them!
For Next Time… • Online lab homework due Wednesday • Written homework due Friday • Online Math Exam due Sunday • Lab this week! Pick 3 partners!