Force. Normal force Illustration The normal force acts on any object that touches surface (either directly or indirectly). The normal force would be applied.

Slides:

Advertisements

Similar presentations

Chapter 11 Angular Momentum

Advertisements

Section 1: The Nature of Force Force – a push or pull on an object; causes an object to accelerate. 0 m/s 3 m/s.

Friction. Friction - the force needed to drag one object across another. (at a constant velocity) Depends on: How hard the surfaces are held together.

Chapter 4 Forces in One Dimension

The Laws of Motion Physics 2053 Lecture Notes The Laws of Motion.

Aim: More friction Do Now:

Friction & Circular Motion

“ If I have seen farther than others, it is because I have stood on the shoulders of giants.” Sir Isaac Newton (1642 – 1727) Physicist.

Chapter 11: Rolling Motion, Torque and Angular Momentum

Chapter 12: Rolling, Torque and Angular Momentum.

Chapter 8 Rotational Equilibrium and Rotational Dynamics.

Rotational Dynamics. Moment of Inertia The angular acceleration of a rotating rigid body is proportional to the net applied torque:  is inversely proportional.

Newton’s 3rd Law: More Practice

Aim: How can we calculate static and kinetic friction? A 3.5 kilogram box is being pulled to the right with a force of 15 newtons. The box is moving at.

Friction and the Coefficients of Friction

Holt Physics Chapter 4 Section 4 Pages

Forces Mass, Weight, and Friction. Weight Weight: force of gravity on an object - on Earth your weight is a direct measure of the planet’s force pulling.

Forces Ch. 6 Milbank High School. Sec 6.1 Force and Motion ► Objectives  Define a force and differentiate between contact forces and long-range forces.

Robot Physics: Part 1 By: Danica Chang and Pavan Datta Team 115.

Forces and the Laws of Motion Force, Mass, and Acceleration

Chapter 5 Newton’s Second Law of Motion – Force and Acceleration

Aim: How can we define friction? Do Now: A 20 kg object is being pulled across a table at a constant velocity with a force of 58.8 N. Draw a free-body.

Physics 1210/1310 Mechanics& Thermodynamics Thermodynamics Lecture R1-7 Rotational Motion.

CHAPTER 3. Newton’s Second Law of Motion F = m × a Force = mass × acceleration The faster you run into a wall, the more force you exert on that wall Units.

8.4. Newton’s Second Law for Rotational Motion

Chapter 9: Rotational Dynamics

Forces and the Laws of Motion Chapter Changes in Motion Objectives  Describe how force affects the motion of an object  Interpret and construct.

Rolling, Torque, and Angular Momentum

Dynamics Forces & Motion. Characteristics of Force A force acting on an object will either: a. change the object’s motion b. cause a deformation in the.

Newton’s Second Law of Motion. Force and Acceleration Force is a push or a pull acting on an object. Acceleration occurs when the VELOCITY of an object.

Friction The force between two surfaces in contact that causes a resistance of the motion or pending motion between the surfaces.

1 Law of friction Properties of frictional force surface between two bodies 1.act along the surface between two bodies oppose relative motion 2.act in.

Phys 250 Ch4 p1 Force and Motion Some History: The Copernican Revolution with Copernicus, Galileo, Kepler... Newton’s Principia: laws of motion physics.

FORCES. A force is an influence on a system or object which, acting alone, will cause the motion of the system or object to change. If a system or object.

Chapters 5-6 Test Review Forces & Motion Forces  “a push or a pull”  A force can start an object in motion or change the motion of an object.  A force.

Forces & Motion Chapter 12.  Newton ’ s first law of motion - an object at rest remains at rest and an object in motion maintains its velocity unless.

1.To understand what momentum is 2.To understand conservation of momentum and to be able to complete related calculations 3.To understand different types.

Chapter 4-4 Weight, Force, and Friction. Weight Weight is the magnitude of the force of gravity acting on an object. Weight = Fg Fg = mass x gravity.

Remember!!!! Force Vocabulary is due tomorrow

Newton’s Laws of Motion

Concept Summary. Momentum  Momentum is what Newton called the “quantity of motion” of an object.

Friction Ffriction = μFNormal.

Friction What is friction?. Answer Me!!! Think of two factors that affect friction.

Period 2 Question 1.

Friction F f is a force that acts between 2 touching objects always parallel to the 2 surfaces in contact always opposite the direction of (attempted)

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.

Friction. Consider An Object Coming to Rest Aristotle’s idea: Rest is the “natural state” of terrestrial objects Newton’s view: A moving object comes.

Newton’s 1 st Law of Motion. Newton’s 1 st Law Newton’s 1 st Law: An object at rest stays at rest and an object in motion stays in motion, unless acted.

Coefficient of Friction The force of friction is directly proportional to the normal force. When we increase the mass or acceleration of an object we also.

1 Work in Rotational Motion Find the work done by a force on the object as it rotates through an infinitesimal distance ds = r d  The radial component.

Newton’s 1 st Law of Motion. Newton’s 1 st Law Newton’s 1 st Law: An object at _______stays at _______and an object in motion stays in motion, unless.

Chapter 9 Rotational Dynamics

Key Concepts What is Newton’s first law of motion? What is Newton’s second law of motion? Key Terms - Inertia.

 car crashes car crashes 

What is the deal with friction?. Friction Force that opposes the motion of objects that touch as they move past each other. 4 types of friction –Static.

Do Now: A boy pushes a 5Kg box across a floor with a force of 40N. If the force of friction is 10N find the acceleration of the box. (Draw a force diagram)

1 Physics: Chapter 4 Forces & the Laws of Motion Topics:4-1 Changes in Motion 4-2 Newton’s First Law 4-3 Newton’s Second & Third Laws 4-4 Everyday Forces.

Resources Section 1 Laws of Motion Objectives Identify the law that says that objects change their motion only when a net force is applied. Relate the.

EnergyDefinitions 1 Different kinds of energy Kinetic energy Kinetic energy is motion energy. The faster it moves the more kinetic energy it possesses.

Section 1: The Nature of Force

Different kinds of energy

Rolling, Torque, and Angular Momentum

Aim: How do we explain the conservation of angular momentum?

11.7 Angular Momentum Figure shows a particle of mass m with linear momentum as it passes through point A in an xy plane. The angular.

Friction and the Coefficients of Friction

Presentation transcript:

Force

Normal force Illustration The normal force acts on any object that touches surface (either directly or indirectly). The normal force would be applied on a ball on a table, but not on a ball in the air, for instance. It always acts perpendicularly to the surface.

The normal force is F N = - mg where: F N is the normal force in Newton (N), m is the mass in kg, and g is the gravitational force in m/s 2.

Friction force and Coefficient of friction

Force of friction F f can be calculated by the formula F f = µ F N where: F f is the force of friction in N, µ is the coefficient of friction, and F N is the normal force in N.

The value of µ depends on surface you are dealing with. The following table shows some example of µ. SurfaceValue of µ rubber on dry asphalt~1 rubber on wet asphalt0.95 steel on steel0.18 steel on ice0.010 rubber on ice0.005

Torque in rigid body Friction torque is a measure of how much a force acting on an object causes that object to rotate.

Static friction – friction force while it is greater than applied force, as a result the applied force give no motion to the subject. Kinetic friction – friction force that acting while the subject/object is in motion because of applied force.

Torque of friction Force acting on the moving object result to the torque of friction. The direction of the rotation due to the resultant force of friction. – Refer to the figure slide 3

Moment Force about a pint – Moment is a force of measure of its tendency to cause a body to rotate about a specific point or axis. – Perpendicular force to the moment arm Example of simple beams

Momentum Force that causes it hard to stop an object. If you were running, you would have momentum. Because of this, if you tried to stop really fast, you might fall because the momentum wants you to keep going forward. Momentum is define by: » mv where m and v are the mass and the velocity of the object respectively Figure: In a crash test. Much of the car’s initial kinetic energy is transformed into the energy it took to damage the vehicle

Conservation of momentum Isolated system – When no net external force acts on a system, the total momentum of the system remains constant in time. Σ m i v i = Σ m f v f

Concept