Lecture 5

Lecture 5 - Physics 110 - Lesson 5 Announcements: Homework...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
Physics 110 - Lesson 5 Announcements: Homework 2 - due Wednesday Discussion session alternative – contact TAs for appointment Textbook on 24-hr reserve at Circ. Desk at Bass Lib. use library computer for instructions - or - ask for monograph 1335 Today’s Lesson : Friction (finish Chapter 4) Newton’s Third Law Applications - Friction Why is it difficult to stop a car in the winter? Circular Motion (Chapter 5) Planetary Motion Keppler’s Laws Universal Gravitation
Background image of page 1

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

View Full DocumentRight Arrow Icon
End of Last Class - Rocket cart demo!! Think about: The cause of the motion & the forces! Why was there motion? Was there acceleration? Would this work in space? What were the forces?
Background image of page 2
Newton’s Third Law: “For every action there is an equal and opposite reaction” Forces can only occur in pairs Cannot produce a force without interacting What Provides the Reactive Force to: My Weight While Standing on a Table? A Push on a Chair? A Pull on a Rope? CAUTION: Action/reaction forces do not change motion!!! Action/reaction forces act on DIFFERENT objects. Demo - Air cart collisions.
Background image of page 3

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

View Full DocumentRight Arrow Icon
Newton’s Third Law - continued Action and Reaction Forces: note that ACTION is “when A exerts a force on B” the REACTION is “B exerts a force on A”
Background image of page 4
Newton’s Third Law - Details Consider a hammer driving a nail. Newton realized: “a single isolated force cannot exist.” Forces in nature always exist in pairs! Newton’s third law. Action-reaction pairs are always exerted on different objects! hammer on nail - action nail on hammer - reaction Since action and reaction are exactly equal and oppositely directed, how can there ever be a net force on an object? There is a difference between: ACTION/REACTION force pairs NET force
Background image of page 5

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

View Full DocumentRight Arrow Icon
Newton’s Third Law Example – I push a block (for Web only) F me on block F friction of floor on block = m a horizontal I push on a block with a force F me on block . The block pushes back with a force –F block on me
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/07/2008 for the course PHYS 110 taught by Professor Johnharris during the Spring '08 term at Yale.

Page1 / 20

Lecture 5 - Physics 110 - Lesson 5 Announcements: Homework...

This preview shows document pages 1 - 7. Sign up to view the full document.

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