Chapter 7.2 Notes Angular Momentum.

Slides:

Advertisements

Similar presentations

Chapter 9 Momentum and Its Conservation

Advertisements

Comparing rotational and linear motion

Rotational Motion October 31, 2005 and November 2, 2005.

A 40-kg mass placed 1.25 m on the opposite side of the support point balances a mass of 25 kg, placed (x) m from the support point of a uniform beam. What.

Angular Impulse Chapter 13 KINE 3301 Biomechanics of Human Movement.

Torque Web Quest Helpful Hints Part I: Definition of Torque Torque is defined as the tendency to produce a change in rotational motion. Examples:

Chapter 11: Rolling Motion, Torque and Angular Momentum

Chapter 9 Rotational Dynamics.

Rotational Inertia and Angular Momentum. Inertia The resistance of an object to change its state of motion Depends on mass (the bigger the mass, the bigger.

Rotational Motion - refers to motion of a body about a fixed axis of rotation wherein, the particles have the same instantaneous angular velocity.

Rotational Motion – Part II

Chapter 8 Rotational Equilibrium and Rotational Dynamics.

Chapter 11 Rotational Dynamics and Static Equilibrium

Department of Physics and Applied Physics , F2010, Lecture 19 Physics I LECTURE 19 11/17/10.

Angular Momentum. Inertia and Velocity  In the law of action we began with mass and acceleration F = maF = ma  This was generalized to use momentum:

Torque and the vector product

Chapter 8 Lecture 2 Rotational Inertia I.Rotational Inertia A.Newton’s 2 nd law: F = ma 1)Rewrite for Rotational Motion  = m  2)But, should we really.

Angular Momentum Angular momentum of rigid bodies

Chap. 11B - Rigid Body Rotation

-Angular Momentum of a Rigid Object -Conservation of Angular Momentum AP Physics C Mrs. Coyle.

\Rotational Motion. Rotational Inertia and Newton’s Second Law  In linear motion, net force and mass determine the acceleration of an object.  For rotational.

8.4. Newton’s Second Law for Rotational Motion

Rotational Dynamics and Static Equilibrium (Cont.)

Student is expected to understand the physics of rotating objects.

Torque Chap 8 Units: m N 2.

Rotational Motion Chapter 6, 8 and 9. Acceleration in a Circle  Acceleration occurs when velocity changes  This means either speed OR direction changes.

Rotational Dynamics Chapter 8 Section 3.

Bouncing and Momentum Change

The center of gravity of an object is the point at which its weight can be considered to be located.

A car of mass 1000 kg moves with a speed of 60 m/s on a circular track of radius 110 m. What is the magnitude of its angular momentum (in kg·m 2 /s) relative.

9.4. Newton’s Second Law for Rotational Motion A model airplane on a guideline has a mass m and is flying on a circle of radius r (top view). A net tangential.

8.2 Rotational Dynamics How do you get a ruler to spin on the end of a pencil? Apply a force perpendicular to the ruler. The ruler is the lever arm How.

Impulse and Momentum Impulse and momentum stem from Newton’s Second Law: Impulse (FΔt): The product of the force and the time it acts on an object. (N·s)

Rotational Motion Part 3 By: Heather Britton. Rotational Motion Rotational kinetic energy - the energy an object possesses by rotating Like other forms.

Announcements Homework: Chapter 7 # 43, 44, 45 & 46 Solutions will be posted Monday afternoon. Exam 2 is next time. Will cover cratering, radioactive decay,

Rolling motion (axis of rotation is moving) Torque Angular momentum Angular momentum is conserved Chapter 11: Angular Momentum part 2 Reading assignment:

NM Unit 8 Topic(s): Angular Momentum Learning Goals: Adapt linear collision analysis for rotational collision analysis Develop a solution strategy to solve.

Angular Momentum. Angular Momentum ( L ) Conservation of Momentum The total angular momentum of a rotating object remains constant if the net torque.

 Angular momentum is a quantity that tells us how hard it is to change the rotational motion of a particular spinning body  Objects with lots of angular.

Rotational Dynamics The action of forces and torques on rigid object: Which object would be best to put a screw into a very dense, hard wood? A B= either.

Rotational Dynamics 8.3. Newton’s Second Law of Rotation Net positive torque, counterclockwise acceleration. Net negative torque, clockwise acceleration.

Moments of INERTIA. Review of Inertia Inertia – Objects with mass always resist a change in there motion (acceleration). From Newton’s second law we see.

Cutnell/Johnson Physics 8th edition Reading Quiz Questions

Rotational or Angular Motion. When an object ’ s center of mass moves from one place to another, we call it linear motion or translational motion.

Motion IV Rotary Motion. Moment/Torque The moment or torque is the tendency of a force to rotate a body about a specified axis or point. Moment is denoted.

Rotational or Angular Motion. When an object ’ s center of mass moves from one place to another, we call it linear motion or translational motion.

Torque and Rotational Motion AP Physics 1. Angular Kinematics.

Rotational Motion AP Physics C. Introduction The motion of a rigid body (an object with a definite shape that does not change) can be analyzed as the.

Rotational Dynamics The Action of Forces and Torques on Rigid Objects

Rotational Mechanics 1 We know that objects rotate due to the presence of torque acting on the object. The same principles that were true for what caused.

Pgs Chapter 8 Rotational Equilibrium and Dynamics.

Rotational Dynamics.

Year 13 Physics Rotation & Circular Motion. Rotation When either a rigid body or a particle rotates about some fixed point, we can describe the motion.

TORQUE A torque is an action that causes objects to rotate. Torque is not the same thing as force. For rotational motion, the torque is what is most directly.

Angular Momentum. Definition of Angular Momentum First – definition of torque: τ = Frsinθ the direction is either clockwise or counterclockwise a net.

Rotational Motion Rotational Inertia – inertia is how an object resists changing its motion so rotational inertia is how much an object resists changing.

Angular Momentum Section 10-9.

Angular Momentum 7.2.

Unit 7 - Rotational Mechanics

Rotational Inertia and Torque

Rotational Equilibrium and Dynamics

Angular Momentum.

Center of Mass & Rotational Inertia

Warm-up (9/26/18) How does one calculate linear momentum?

Remember Newton’s 2nd Law?

Rotational Kinematics

Remember Newton’s 2nd Law?

Newton’s Laws of Motion

Angular Momentum.

Chapter 8 Rotational Equilibrium and Dynamics

Presentation transcript:

Chapter 7.2 Notes Angular Momentum

Angular momentum tells us how difficult it is to stop a rotating object.

Equation for angular momentum = Inertia x angular velocity L = Iw

Objects of equal mass but different shapes have different inertia.

Equations for Inertia range from: Circular Orbit = I = 2/3mr2 Solid Cylinder = I = 1/2mr2 (I’ll tell you which equation to use)

A basketball has a mass of. 005 kg. The ball has a diameter of A basketball has a mass of .005 kg. The ball has a diameter of .8m and is a sphere so we use the equation I = 2/3 mr2. The angular speed of the ball is 30 rad/s. What is the angular momentum? Radius = Diameter / 2 = .8 m / 2 = .4 m I=2/3mr2=2/3(.05g)(.4m)2 =.0005 kg/m2 L = Iw = (.0005)(30) = .016 kg·m2 / s

Newton’s 2nd law of motion with angular momentum – Equations = Torque = Angular momentum / time T = L / t

An astronaut grabs a satellite to stop it from spinning An astronaut grabs a satellite to stop it from spinning. The satellite mass is 900 kg, and it is spinning at 1 rad/s. The radius is .7 m. The astronaut must hold the satellite of .5 seconds, what torque is required to stop the spin? To find the Inertia use I = ½ mr2 T=L/t; First find L (angular momentum) T = 220.5 / .5 = 441

Angular impulse (equation) = Torque x time Since angular impulse = change in angular momentum (equation) = Tt = L

A 100 kg potter’s wheel is 2 meters in radius A 100 kg potter’s wheel is 2 meters in radius. What is the torque if the time is 10 seconds and the equation for I=1/2 mr2 and the angular speed of the wheel is 22 rad/s? Tt = L First find L (angular momentum) T(10) = 4400 T = 4400 / 10 = 440

Law of conservation of angular momentum says that when no net external torque acts on a closed system, the total angular momentum of the system does not change.

Rotating Stool Demo

Law of conservation of angular momentum equation = L1 = L2 I1w1 = I2w2

If a skater starts with a moment of inertia of 5 with a speed of 2 than he brings in this arm to change his moment of inertia to 2. What happens to his speed? I1w1 = I2w2 5(2) = 2(w2) 10 = 2w2 w2 = 5