{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Lect02

# Lect02 - Physics112:Lecture2 AgendaforToday 1DKinematics...

This preview shows pages 1–9. Sign up to view the full content.

QuickTimeª and a TIFF (Uncompressed) decompressor are needed to see this picture. Physics 112: Lecture 2 Agenda for Today 1-D Kinematics 1-D Kinematics Average & instantaneous velocity and acceleration Motion with constant acceleration QuickTimeª and a TIFF (Uncompressed) decompressor are needed to see this picture.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Motion in 1 dimension In 1-D, we usually write position as x(t). Since it’s in 1-D, all we need to indicate direction is + or - . Displacement in a time t = t 2 - t 1 is x = x(t 2 ) - x(t 1 ) = x 2 - x 1 t x t 1 t 2 x t x x some particle’s trajectory in 1-D
1-D kinematics t x t t ) t ( x ) t ( x v 1 2 1 2 av = - - t x t 1 t 2 x x x trajectory Velocity v is the “rate of change of position” Average velocity v av in the time t = t 2 - t 1 is: t V av = slope of line connecting x 1 and x 2 .

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Consider limit t 1 t 2 Instantaneous velocity v is defined as: 1-D kinematics... dt ) t ( dx ) t ( v = t x t 1 t 2 x x x t so v(t 2 ) = slope of line tangent to path at t 2 .
Puzzle Yesterday I was driving down Green Street, when I was stopped by a police officer. He said to me “You were going 60 miles an hour.” I responded, “I’ve only been driving for 10 minutes! How could I possibly have gone 60 miles an hour, when I haven’t even been traveling for an hour?” What’s wrong with my argument?

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Graph of x(t) versus time, what’s the average velocity? T
Definition of SPEED: distance traveled without regard to direction, divided by time t. What’s the average speed? Average speed average velocity!

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
1-D kinematics... t v t t ) t ( v ) t ( v a 1 2 1 2 av = - - Acceleration a is the “rate of change of velocity” Average acceleration a av in the time t = t 2 - t 1 is: And
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}