{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

sy16_oct29_07hc

# sy16_oct29_07hc - Physics 207 Lecture 12 Physics 207...

This preview shows pages 1–3. Sign up to view the full content.

Page 1 Physics 207 – Lecture 12 Physics 207: Lecture 16, Pg 1 Physics 207, Physics 207, Lecture 16, Oct. 29 Lecture 16, Oct. 29 Agenda: Chapter 13 circle6 Center of Mass Center of Mass circle6 Torque Torque circle6 Moment of Inertia circle6 Rotational Energy circle6 Rotational Momentum Assignment: circle6 Wednesday is an exam review session, Exam will be held in rooms B102 & held in rooms B102 & B130 in Van Vleck at 7:15 PM circle6 MP Homework 7, Ch. 11, 5 problems, MP Homework 7, Ch. 11, 5 problems, NOTE: Due Wednesday at 4 PM circle6 MP Homework 7A, Ch. 13, 5 problems, available soon Physics 207: Lecture 16, Pg 2 Chap. 13: Rotational Dynamics circle6 Up until now rotation has been only in terms of circular motion with a c = v 2 / R and | a T | = d| v | / dt circle6 Rotation is common in the world around us. circle6 Many ideas developed for translational motion are transferable. Physics 207: Lecture 16, Pg 3 Conservation of angular momentum has consequences How does one describe rotation (magnitude and direction)? Physics 207: Lecture 16, Pg 4 Rotational Dynamics: A child Rotational Dynamics: A child’ s toy, a physics playground or a student playground or a student’ s nightmare circle6 A merry-go-round is spinning and we run and jump on it. What does it do? circle6 We are standing on the rim and our “friends” spin it faster. What happens to us? circle6 We are standing on the rim a walk towards the center. Does anything change? Physics 207: Lecture 16, Pg 5 Rotational Variables Rotational Variables circle6 Rotation about a fixed axis: xrhombus Consider a disk rotating about an axis through its center:] circle6 How do we describe the motion: (Analogous to the linear case ) ϖ θ R (rad/s) 2 Tangential v T dt d = = = π θ ϖ dt dx = v Physics 207: Lecture 16, Pg 6 Rotational Variables... circle6 Recall: At a point a distance R away from the axis of rotation, the tangential motion: xrhombus x = θ R xrhombus v = ϖ R xrhombus a = α R ϖ α R v = ϖ R x θ rad) in position (angular 2 1 rad/s) in elocity (angular v ) rad/s in accelation (angular constant 2 0 0 0 2 t t t α ϖ θ θ α ϖ ϖ α + + = + = =

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

View Full Document
Page 2 Physics 207 – Lecture 12 Physics 207: Lecture 16, Pg 7 Summary (with comparison to 1 (with comparison to 1- D kinematics) Angular Linear constant = α ϖ = ϖ 0 + α t θ θ ϖ α = + + 0 0 2 1 2 t t constant = a at + = 0 v v 2 0 0 2 1 v at t x x + + = And for a point at a distance R from the rotation axis: x = R θ v = ϖ R a = α R Physics 207: Lecture 16, Pg 9 Lecture 15, Lecture 15, Exercise 5 Exercise 5 Rotational Definitions circle6 A goofy friend sees a disk spinning and says “Ooh, look! There’s a wheel with a negative ϖ and with antiparallel ϖ and α !” circle6 Which of the following is a true statement about the wheel? (A) (A) The wheel is spinning counter-clockwise and slowing down. (B) (B) The wheel is spinning counter-clockwise and speeding up. (C) (C) The wheel is spinning clockwise and slowing down.
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 10

sy16_oct29_07hc - Physics 207 Lecture 12 Physics 207...

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

View Full Document
Ask a homework question - tutors are online