Velocity And acceleration graphical Interptition
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The document outlines a physics lecture series focusing on mechanics, specifically covering topics such as velocity, acceleration, and motion equations. It details the schedule of lectures, reading materials, and homework assignments from early January to mid-February 2012. Key concepts include graphical interpretation of velocity and acceleration, average and instantaneous values, and examples demonstrating these principles in real-world scenarios.
Velocity And acceleration graphical Interptition
- 1. Physics - Mechanics Lecture 2 Velocity and Acceleration September , 2013
- 2. Physics 114A - Lecture 3 2/19 Physics 114A - Introduction to Mechanics - Winter-2012 Textbook: Physics, Vol. 1 (UW Edition), James S. Walker Week Date L# Lecture Topic Pages Slides Reading HW Due Lab 1 2-Jan-12 H1 New Year Holiday No Lab 1st week 3-Jan-12 1 Introduction to Physics 12 21 Chapter 1 5-Jan-12 2 Position & Velocity 8 22 2-1 to 2-3 No HW 6-Jan-12 3 Velocity & Acceleration 10 25 2-4 to 2-5 2 9-Jan-12 4 Equations of Motion 9 20 2-6 to 2-7 1-D Kinematics 10-Jan-12 5 Vectors 8 24 3-1 to 3-3 12-Jan-12 6 r, v & a Vectors 5 24 3-4 to 3-5 HW1 13-Jan-12 7 Relative Motion 3 18 3-6 3 16-Jan-12 H2 MLK Birthhday Holiday Free Fall & Projectiles 17-Jan-12 8 2D Motion Basics 5 19 4-1 to 4-2 19-Jan-12 9 2D Examples 13 22 4-3 to 4-5 HW2 20-Jan-12 E1 EXAM 1 - Chapters 1-4 Lecture Schedule (Part 1) We are here.
- 4. 4/19 Graphical Interpretation of Average & Instantaneous Velocity
- 5. 5/19 Velocity & Slope The position vs. time graph of a particle moving at constant velocity has a constant slope. The position vs. time graph of a particle moving with a changing velocity has a changing slope. 3.0 s 4.5 m slope = velocity = 4.5 m/3.0 s = 1.5 m/s
- 6. 6/19 Constant Acceleration 0 0 avx x x xv v v v a t av if is constantx x xa a a Acceleration characterizes the change in velocity with time: v/t. If the acceleration is constant, then the velocity is changing at a constant rate. Graphically, if we plot the velocity vs. time, it will fall on a straight line with a slope determined by the acceleration.
- 7. 7/19 Acceleration , ,(so t) fx ixx av x x av x f i v vv a v a t t t 0 ( ) lim x x t v a t t Average acceleration: Instantaneous acceleration: Acceleration units: (m/s)/s = m/s2
- 8. 8/19 Position, Velocity, & Acceleration Velocity negative; acceleration negative. Velocity positive; acceleration zero. Velocity positive; acceleration negative. Velocity positive; acceleration positive. Velocity zero; acceleration zero.
- 10. 10/19 Graphical Interpretation of Average and Instantaneous Acceleration: Acceleration
- 11. 11/19 Example: An Accelerating Train A train moving in a straight line with an initial velocity of 0.50 m/s accelerates at 2.0 m/s2 for 2.0 s, coasts with zero acceleration for 3.0 s, and then accelerates at -1.5 m/s2 for 1.0 s. (a) What is the final velocity vf of the train? (b) What is the average acceleration aav of the train? 2(3.0 m/s) (0.5 m/s) 0.42 m/s (6.0 s) (0 s) f i av f i v vv a t t t 1 1 2 2 3 3 2 2 2 (0.50 m/s) (2.0 m/s )(2.0 s) (0 m/s )(3.0 s) ( 1.5 m/s )(1.0 s) 3.0 m/s f i iv v v v a t a t a t
- 12. 12/19 Acceleration (increasing speed) and deceleration (decreasing speed) should not be confused with the directions of velocity and acceleration: Acceleration vs. Deceleration Accelerating Accelerating Decelerating Decelerating
- 13. 13/19 Motion with Constant Acceleration If the acceleration is constant, the velocity changes linearly: (2-7) Constant Acceleration Changing Acceleration1 02 ( )avv v v Slope Constant Slope Changing
- 14. 14/19 Motion with Constant Acceleration Velocity vs. time: (2-7) Average velocity: (2-9) Position as a function of time: (2-10) (2-11) Velocity as a function of position: (2-12)
- 15. 15/19 Motion with Constant Acceleration The relationship between position and time follows a characteristic curve. Parabola
- 16. 16/19 Motion with Constant Acceleration
- 17. 17/19 A park ranger driving at 11.4 m/s in back country suddenly sees a deer “frozen” in the headlights. He applies the brakes and slows with an acceleration of 3.80 m/s2. (a) If the deer is 20.0 m from the ranger’s car when the brakes are applied, how close does the ranger come to hitting the deer? (b) What is the stopping time? 2 2 2 2 0 2 (0) (11.4 m/s) 17.1 m 2 2( 3.80 m/s ) v v x a 20.0 m 17.1 m 2.9 md 0 0 2 (11.4 m/s) 0 3.00 s ( 3.80 m/s ) v v v at t a Example: Hit the Brakes!