Lecture09_Pushkar_tentative

Lecture09_Pushkar_tentative - Lecture 9 Purdue University,...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Lecture 9 Purdue University, Physics 220 1 Lecture 9 Work and Kinetic Energy PHYSICS 220 Lecture 9 Purdue University, Physics 220 2 Energy • Energy is “conserved” meaning it can not be created nor destroyed – Can change form – Can be transferred • Total Energy of an isolated system does not change with time • Types – Kinetic Energy – Potential Energy – Rest Energy (E=mc 2 ) – Thermal Energy – … … • Units: Joule (J) = N m = kg m 2 / s 2 Lecture 9 Purdue University, Physics 220 3 Work and Energy θ • Work: Transfer of Energy by Force W = | F | | ∆ r | cos θ • Kinetic Energy (Energy of Motion) KE = 1/2 mv 2 • Work-Kinetic Energy Theorem: Σ W = ∆ KE Lecture 9 Purdue University, Physics 220 4 Work by Constant Force • Only component of force parallel to direction of motion does work! W = F ∆ r cos θ F θ ∆ r F W F > 0: 0< θ < 90 : cos( θ ) > 0 ∆ r F W F = 0: θ =90 : cos( θ ) =0 ∆ r F W F < 0: 90< θ < 270 : cos( θ ) < 0 ∆ r F W > 0: 0< θ < 90 : cos( θ ) > 0 Lecture 9 Purdue University, Physics 220 5 Work by Constant Force • Example: You pull a 30 N chest 5 meters across the floor at a constant speed by applying a force of 50 N at an angle of 30 degrees. How much work is done by the 50 N force?...
View Full Document

This note was uploaded on 04/23/2011 for the course PHYS 220 taught by Professor Chang during the Spring '09 term at Purdue University.

Page1 / 18

Lecture09_Pushkar_tentative - Lecture 9 Purdue University,...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online