Aim: How do we explain Newton’s 3rd Law?

Slides:

Advertisements

Similar presentations

Q4.1 You are standing at rest and begin to walk forward. What force pushes you forward? 1. the force of your feet on your ground 2. the force of your acceleration.

Advertisements

Newton’s 3rd Law Whenever one object exerts a force on a second object the second object exerts a force equal in strength, BUT opposite in direction back.

More on Newton’s 3 rd Law. Conceptual Example 4-4: What exerts the force to move a car? Response: A common answer is that the engine makes the car move.

Newton’s Laws and the Motion of Particles Teacher Excellence Workshop June 19, 2009.

Newton's First Law of Motion

Warm-up 1. If a toy train has a mass of 1.5 kg & accelerates at a rate of 20 m/s2, what is the amount of force acting on it? 2. Make a Venn diagram comparing/contrasting.

Friction Gravity Newton’s Laws Momentum Forces.

Weight is a force that is defined from the gravitational attraction between two masses. The gravitational force causes the less massive object to accelerate.

Newton’s Third Law of Motion. Momentum.

Free Body Force Diagrams and Newton’s Third Law

Consider a horse pulling a buggy. Is the following statement true?

Newton’s Second and Third Laws

Nahdir Austin Honors Physics Period 2.  Force: A push or pull on an object (something that can accelerate objects.  A force is measured by a Newton.

A ball is lying on a table. The forces on the ball are sketched on the right. Here N is the force of the table pushing up on the ball, to keep it from.

What is Newton’s 3 rd Law? The Questions.  Newton’s 3 rd Law says that for every action force there must be an equal and opposite reaction force.  The.

Newton’s Laws of Motion 1. If the sum of all external forces on an object is zero, then its speed and direction will not change. Inertia 2. If a nonzero.

Do Now: What are Newton’s 3 Laws of Motion?. Do Now: What are Newton’s 3 Laws of Motion?

Newton’s 2 nd Law. Enduring Understanding: Studying dynamics (causes of motion) has had a profound effect on the way humans view their world. Essential.

Newton’s Laws of Motion

Newton’s Third Law. Did you know that when you push against a wall, it pushes back? No, the wall isn’t “getting pushy.” But why don’t you move the wall?

Chapter 4 Forces and the Laws of Motion. Newton’s First Law An object at rest remains at rest, and an object in motion continues in motion with constant.

FORCE. A FORCE IS A PUSH OR A PULL. IF FORCES ARE POWERFUL ENOUGH, THEY MAY RESULT IN MOTION.  What is a force?

For every force, there is an equal and opposite force.

Newton’s Laws. Basic Laws of Biomechanics Sir Isaac Newton developed three laws to explain the relationship between forces acting on a body and the motion.

In this section you will:

Chapter: Force and Newton’s Laws

Newton’s Laws of Motion

Newton’s Laws AP Physics C. Basic Definitions  Inertia  property of matter that resists changes in its motion.  Mass  measurement of inertia  Force.

 Force: A push or a pull Describes why objects move Defined by Sir Isaac Newton.

More on Newton’s 3 rd Law. Conceptual Example: What exerts the force to move a car? Response: A common answer is that the engine makes the car move forward.

4.3 NEWTON’S THIRD LAW All forces occur in interaction pairs. tbn2.gstatic.com/images?q=tbn:ANd9GcSCEAv2yl7JcoFX_7JVm6HaIzocEfYw0HkWuI7lUSITPj.

Ch. 3 & 4 Motion & Forces VI. Action and Reaction  Newton’s Third Law  Momentum  Conservation of Momentum.

Newton’s Third Law of Motion In any interaction between two objects, the forces exerted are always equal in magnitude and opposite in direction. “For every.

Force and Newton’s Laws. Section 1 ndtime/newtonslawsofmotion/

Forces & The Laws of Motion Ideas of Sir Isaac newton.

The Nature of Force Newton’s Laws.

Newton’s Third Law of Motion

Newton’s third law of motion 1 Force 2

Newton’s Third Law.

Force is part of an interaction

Newton’s third law Forces always come in pairs, one on each object in the pair. The magnitudes of the forces in a pair are always ________, and the direction.

Today Finish Newton’s Laws More Forces.

Physics Section 4.3 Apply Newton’s 2nd and 3rd Law of Motion

The Joy of Physics Sisyphus Newton’s Laws.

Newton’s 3rd law.

CHAPTER 6 NEWTON’S THIRD LAW.

Force is part of an interaction

Newton’s Laws.

Aim: How do we explain Newton’s 3rd Law?

Newton’s Second Law 1.

Today Finish Newton’s Laws More Forces.

Newton’s Laws of Motion

Forces & Motion Quiz.

Forces Georgia Performance Standards

Newton’s 2nd Law of Motion

What is Newton’s 3rd Law of Motion?

Newton’s Second Law 1.

4.3 Netwon’s Second and Third Laws

Forces and Newton’s Laws of Motion

Textbook: 4.5 Homework: WS - Newton’s Third Law

Chunk 4 Newton’s Laws of Motion.

Forces Review 8th Grade Science.

NEWTON'S THIRD LAW OF MOTION.

In your Journals: Quickwrite on Forces

Newton’s Third Law Chapter 13 Section 3 Part 3.

Newton’s Third Law Chapter 13 Section 3 Part 3.

Objective SWBAT explain Newton’s third law and use it to explain the movement of objects.

Section 2.3 Forces act in pairs

Newton’s Third Law Chapter 13 Section 3 Part 3.

Newton’s Third Law Chapter 13 Section 3 Part 3.

Presentation transcript:

Aim: How do we explain Newton’s 3rd Law?

Explain this

Newton’s Third Law When two objects interact, they exert forces on each other. Newton’s Third Law says “The force object A exerts on object B is equal and opposite to the force that object B exerts on object A” These forces form an action-reaction pair

Newton’s Third Law Action-Reaction Pairs

Newton’s Third Law Paradox A donkey starts to pull a cart (he exerts a force in one direction). The cart therefore exerts the same amount of force on the donkey (a force in the opposite direction). (Newton's third law: For every action, there is an equal and opposite reaction.) So how can the donkey pull the cart if the cart exerts the same amount of force on the donkey in the opposite direction? Should he not move?

Donkey-Cart Paradox

Why can the Donkey move? The cart’s force is only in reaction to the horse’s force so it does not define the direction of movement. The forward and backward forces are equal, so it actually can’t move forward. The forward force of the horse is just big enough to overcome the backward force of the cart and start the cart forward The cart is rolling on wheels while the horse’s hooves have traction with the ground There is a brief moment where the horse pulls before the reaction force kicks in

Donkey-Cart Paradox Resolved Remember there are two different objects to consider here: the horse and the wagon.

Thought Question Do the forces weight and normal force as shown below form an action-reaction pair? They do not because both forces act on the same object

Contact Force Problem 1 (Assume no friction) A 2kg and 8kg box are pushed by a 40 N force across a frictionless surface. Calculate the contact force between the two boxes.

Contact Force Problem 2 (Assume no friction) A 3kg box, 5 kg box, and 2 kg box are pushed together by a force of 54 N across a frictionless surface. Find the contact force between the 3 kg box and the 5 kg box. Find the contact force between the 5 kg box and the 2 kg box.

Multiple Block Problem A force F=12 N is pushing three adjacent blocks across a frictionless surface of masses (m1 = 1 kg, m2=2kg, and m3 = 3kg. What is the acceleration of each block? What is the net force on m1? What is the magnitude of the force m1 exerts on m2? What is the magnitude of the force that m2 exerts on m3?