This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: January 26, 2006 Physics for Scientists&Engineers 1 1 Physics for Scientists & Physics for Scientists & Engineers 1 Engineers 1 Spring Semester 2006 Lecture 9 January 26, 2006 Physics for Scientists&Engineers 1 2 ! Horizontal motion: constant velocity Review: Yesterday (1) Review: Yesterday (1) (1) x = x + v x t (2) v x = v x 2 1 2 1 2 2 2 (3) (4) ( ) (5) (6) (7) 2 ( ) y y y y y y y y y y y v t gt v v gt y y v t v v v v v g y y = + ! = ! = + = + = ! ! v x ! v x ( t = 0); v y ! v y ( t = 0) ! Vertical motion: free fall ! Use notation convention: January 26, 2006 Physics for Scientists&Engineers 1 3 Review: Yesterday (2) Review: Yesterday (2) ! Trajectory is a parabola in space (xy-plane) for x 0 =0 y = y + v y v x x ! g 2 v x 2 x 2 y = y + x tan ! " g 2 v 2 cos 2 ! x 2 or: y x cos sin x y v v v v ! ! = = Thanks to January 26, 2006 Physics for Scientists&Engineers 1 4 v(t) v(t) ! Look at x- and y-components separately v ( t ) t v x ( t ) v x v y ( t ) v y S l o p e =- g t = v y / g (1) (2 ( ) ( ) ) x x y y v t v v t v gt = = ! ! Horizontal component is constant in time ! Vertical component falls in time, with slope -g ! Note: if vertical velocity starts positive, it will reach a point at which it is 0. January 26, 2006 Physics for Scientists&Engineers 1 5 v(t) and Trajectory v(t) and Trajectory ! Snapshots of velocity vectors on trajectory at different times • Green arrows : horizontal v-component • Red arrows : vertical v-component • Blue arrows : velocity vector ! Important: velocity vector forms tangent at every point of trajectory Note: at apex of trajectory, v y changes sign January 26, 2006...
View Full Document
This note was uploaded on 03/19/2008 for the course PHY 183 taught by Professor Wolf during the Spring '08 term at Michigan State University.
- Spring '08