sy13_oct17_07hc

Sy13_oct17_07hc - Page 1 Physics 207 – Lecture 12 Physics 207 Lecture 12 Pg 1 Physics 207 Physics 207 Lecture 13 Oct 15 Lecture 13 Oct 15 Agenda

Info iconThis preview shows pages 1–3. 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
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Page 1 Physics 207 – Lecture 12 Physics 207: Lecture 12, Pg 1 Physics 207, Physics 207, Lecture 13, Oct. 15 Lecture 13, Oct. 15 Agenda: Finish Chapter 10, start Chapter 11 Agenda: Finish Chapter 10, start Chapter 11 Assignment: Assignment: c HW5 due tonight HW5 due tonight c HW6 available today HW6 available today c Monday, finish reading chapter 11 Monday, finish reading chapter 11 • Chapter 10: Energy Chapter 10: Energy x Potential Energy (gravity, springs) x Kinetic energy x Mechanical Energy x Conservation of Energy x Start Chapter 11, Work Physics 207: Lecture 12, Pg 2 Chapter 10: Energy Chapter 10: Energy c Rearranging Newton’s Laws gives (Fd vs . ½ mv 2 relationship)-2mg (y f – y i ) = m (v yf 2 - v yi 2 ) c or b ½ m v yi 2 + mgy i = ½ m v yf 2 + mgy f c and adding ½ m v xi 2 + ½ m v zi 2 and ½ m v xf 2 + ½ m v zf 2 ½ m v i 2 + mgy i = ½ m v f 2 + mgy f c where v i 2 = v xi 2 +v yi 2 + v zi 2 ½ m v 2 terms are referred to as kinetic energy Physics 207: Lecture 12, Pg 3 Energy Energy c If only If only “conservative conservative ” forces are present, the total energy forces are present, the total energy (sum of potential, U, and kinetic energies, K sum of potential, U, and kinetic energies, K ) of a system ) of a system is is conserved conserved . K ½ mv 2 U mgy c K and U may change, but E = K + U mech remains constant. E mech = K + U = constant constant E mech is called “mechanical energy” K i + U i = K f + U f Physics 207: Lecture 12, Pg 4 Another example of a conservative system: Another example of a conservative system: The simple pendulum. The simple pendulum. c Suppose we release a mass m from rest a distance h 1 above its lowest possible point. x What is the maximum speed of the mass and where does this happen ? x To what height h 2 does it rise on the other side ? v h 1 h 2 m Physics 207: Lecture 12, Pg 5 Example: The simple pendulum. Example: The simple pendulum. y y=0 y=h 1 x What is the maximum speed of the mass and where does this happen ? E = K + U = constant and so K is maximum when U is a minimum. Physics 207: Lecture 12, Pg 6 Example: The simple pendulum. Example: The simple pendulum. v h 1 y y=h 1 y=0 x What is the maximum speed of the mass and where does this happen ? E = K + U = constant and so K is maximum when U is a minimum E = mgh 1 at top E = mgh 1 = ½ mv 2 at bottom of the swing Page 2 Physics 207 – Lecture 12 Physics 207: Lecture 12, Pg 7 Example: The simple pendulum. Example: The simple pendulum....
View Full Document

This note was uploaded on 10/30/2011 for the course PHYS 207 taught by Professor Winnokur during the Spring '06 term at Wisconsin.

Page1 / 5

Sy13_oct17_07hc - Page 1 Physics 207 – Lecture 12 Physics 207 Lecture 12 Pg 1 Physics 207 Physics 207 Lecture 13 Oct 15 Lecture 13 Oct 15 Agenda

This preview shows document pages 1 - 3. Sign up to view the full document.

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