JP © 1 2 WHEN FORCES ARE NOT BALANCED A RESULTANT FORCE CHANGES A BODY’S VELOCITY.

Slides:



Advertisements
Similar presentations
Newton’s First Law of Motion Newton’s First Law of Motion.
Advertisements

Newton’s Second Law. But first… Review: Newton’s First Law If an object experiences NO net force…. Resting objects remain at rest. Moving objects move.
Force and motion Forces acting together
Momentum is a measure of inertia in motion. Momentum is equal to mass multiplied by velocity. p = mv.
How Do You Describe Force and the Laws of Motion? Newton’s Laws of Motion They describe the relationship between a body and the forces acting upon it,
Momentum – The Basics Momentum is mass in motion (or inertia in motion) Momentum is abbreviated as the letter p! Momentum is mass x velocity (p = mv) Both.
AMY SHANTA BABOOLAL PHYSICS PROJECT: MECHANICS. ARISTOTLE’S ARGUMENTS One of his well known arguments is: to understand change, a distinction must be.
MOMENTUM Definition: Momentum (Symbol : ….) is defined as the product of the ………….. and ……………. of a moving body. Momentum p = units: ……………. N.B. Since.
Mechanics Topic 2.2 Forces and Dynamics. Forces and Free-body Diagrams To a physicist a force is recognised by the effect or effects that it produces.
Force Chapter 4 (Ewen et al. 2005) Objectives: Related force and the law of inertia. Apply the law of acceleration.
Impulse During any collision some momentum is transferred from one object to another. So… momentum of one object decreases by  p and momentum of the other.
Force. Objective Use the equation: net force = mass x acceleration.
Momentum and Impulse. Answer Me!!! Forces cause objects to start moving. What keeps an object moving after the force is no longer applied?
Honors Physics Newton’s Second Law of Motion.  Newton’s First Law explains the results of zero net external force. –The body stays at rest or moves with.
Sir Isaac Newton Newton’s Laws of Motion Newton’s 1st Law of Motion -An object at rest, will remain at rest, unless acted upon by an unbalanced.
Notes Force. Force is a push or pull exerted on some object. Forces cause changes in velocity. The SI unit for force is the Newton. 1 Newton = 1 kg m/s.
Newton’s Laws of Motion Force is usually assumed push/pull – not easy to describe actual force, but effects of force can be described e.g. movement. Force.
LAWS OF MOTION.
Newton’s 1 st Law Inertia. Force Anything capable of changing an object’s state of motion Any push or pull Causes object to speed up, slow down, or change.
Momentum Webster’s: A property of a moving body that determines the length of time required to bring it to rest when under the action of a constant force.
CONSERVATION OF MOMENTUM. When two particles collide they exert equal and opposite impulses on each other. It follows that for the two particles, the.
Energy Momentum, Collisions, Impulse. Momentum A measure of how hard it is to stop a moving object A measure of how hard it is to stop a moving object.
Linear momentum. The concept of momentum The momentum of a mass m and velocity v is defined to be p = mv Momentum is a vector quantity whose direction.
Motion a change in position in a certain amount of time.
Concept Summary. Momentum  Momentum is what Newton called the “quantity of motion” of an object.
Momentum Momentum is inertia in motion Momentum is inertia in motion What is Inertia? What is Inertia? …think Newton’s 1 st Law …think Newton’s 1 st Law.
Newton’s Laws AP Physics C. Basic Definitions  Inertia  property of matter that resists changes in its motion.  Mass  measurement of inertia  Force.
Unbalanced Forces. Topic Overview A force is a push or a pull applied to an object. A net Force (F net ) is the sum of all the forces on an object (direction.
Unit 2 Momentum and Impulse An Introduction to Momentum.
Jeopardy First Law Second Law Third LawDefinitionsForces Q $100 Q $200 Q $300 Q $400 Q $500 Q $100 Q $200 Q $300 Q $400 Q $500 Final Jeopardy.
FORCE = Any push or pull which causes something to move or change its speed or direction.
1.To revisit Newton’s 2 nd law in terms of momentum. 2.To define the impulse of a force and connect it to the change in momentum 3.To understand the significance.
Homework Read pages 96 – 101 Answer practice problems
Acceleration The rate at which velocity changes. Includes: increasing speed decreasing speed changing direction (with no change in velocity)
If you apply a force to an object, the effect it has depends on the mass of the object and for how long you exert the force. You apply a constant force,
Universal Laws of 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.
Newton’s Second Law of Motion. 2 nd Law of Motion  The net (total) force of an object is equal to the product of its acceleration and its mass.  Force.
NEWTON’S 3 RD LAW The Third Law of Motion. NEWTON’S 3 RD LAW  For every action there is an equal and opposite reaction!
CHAPTER - 9 FORCE AND LAWS OF MOTION CLASS :- IX MADE BY :- VIKAS YADAV SCHOOL :- K.V.
Linear momentum You should be able to: state the definition of momentum; state the definition of average net force in terms of momentum; state the definition.
FORCE: The cause of motion (what causes objects to move) Two types of forces: Push OR a Pull Forces speed things up, slow things down, &/or changes their.
Momentum “Why can you stop a baseball traveling at 40 meters per second but not a car traveling at 1 meter per second?”
Formula Momentum (p) = Mass x velocity Unit is kgm/s.
What are the three fundamental forces outside of the nucleus?
Newton’s laws of motion
S I R I S A A C N E WTON ( ) JP.
newton’s laws of motion
Newton’s Laws Of Motion
Newton’s First and Second Laws
Chapter 4 Forces.
Newton’s Laws of Motion
Chapter 2: Forces and Motion
Momentum:.
Forces.
I. Newton’s Laws of Motion
4.1a Further Mechanics Momentum concepts
Newton’s Laws of Motion
FORCE AND MOTION.
Momentum.
Objective SWBAT describe Newton’s second law of motion and use it to explain the movement of objects.
S I R I S A A C N E WTON ( ) JP ©.
Newton’s First and Second Law
Knowledge Organiser – Motion
AS-Level Maths: Mechanics 1 for Edexcel
CHAPTER - 9 FORCE AND LAWS OF MOTION
I. Newton’s Laws of Motion
Momentum and Impulse Elliott.
Presentation transcript:

JP © 1

2 WHEN FORCES ARE NOT BALANCED A RESULTANT FORCE CHANGES A BODY’S VELOCITY

JP © 3 NEWTON’S SECOND LAW : “THE RATE OF CHANGE OF MOMENTUM OF A BODY IS DIRECTLY PROPORTIONAL TO THE RESULTANT EXTERNAL FORCES ACTING UPON IT, AND TAKES PLACE IN THE DIRECTION OF THAT FORCE”

JP © 4 7 FORCE A RESULTANT FORCE PRODUCES A CHANGE IN A BODY’S MOMENTUM A RESULTANT FORCE AN ACCELERATION

JP © 5 NEWTON 2 If u = initial velocity, v = final velocity and t = time for the change, then F ma F = k ma

JP © 6 F = k ma OUR UNIT OF FORCE, THE NEWTON, IS DEFINED SO THAT k = 1 ONE NEWTON IS THE FORCE THAT CAUSES A MASS OF 1 kg TO ACCELERATE AT 1 m/s 2 F=kma so 1 = k x 1 x 1 so k = 1

JP © 7 NEWTON’S SECOND LAW u n i t s F in Newtons m in kilograms a in metres per second 2

JP © 8 ACCELERATION IS DIRECTLY PROPORTIONAL TO THE APPLIED FORCE acceleration / ms -2 force / N N.B. - STRAIGHT LINE THROUGH THE ORIGIN

JP © 9 mass / kg GRAPH OF ACCELERATION VERSUS MASS acceleration / ms -2 F = m a

JP © 10 ACCELERATION IS INVERSELY PROPORTIONAL TO MASS OF THE BODY acceleration / ms -2 N.B. - STRAIGHT LINE THROUGH THE ORIGIN

JP © 11 NEWTON’S SECOND LAW IS USED IN TWO FORMS Where F is the RESULTANT FORCE

JP © 12 A railway engine pulls a wagon of mass 10 tonnes along a level track at a constant velocity. The pull force in the couplings between the engine and wagon is 1000 N. (A)What is the force opposing the motion of the wagon? (B)If the pull force is increased to 1400 N and the resistance to movement of the wagon remains constant, what would be the acceleration of the wagon? QUESTION The speed is steady, so by Newton’s first law, the resultant force must be zero. The pull on the wagon must equal the resistance to motion. Answer is 1000 N The resultant force on the wagon is 1400 – 1000 = 400 N. Acceleration = Force ÷ mass = 400 ÷ = 0.04 ms -2

JP © 13 Ft = mv - mu IMPULSE IMPULSE = the product of a force and the time that the force is applied for. UNITS = Newton seconds, Ns. IMPULSE = CHANGE OF MOMENTUM

JP © 14 Force-Time Graphs The force applied to a body is rarely constant. Physicists tend to consider the force as a function of time and plot a graph of Force versus Time. force / N Time / s Impulse = Area under the graph = Change in momentum

JP © 15 “I’ve just crashed into a haystack!” “I’ve just crashed into a brick wall!” BOTH CARS HAD THE SAME MASS AND WERE TRAVELLING AT THE SAME SPEED force / N Time / s B A IDENTIFY WHICH COLLISIONS IS A AND WHICH IS B. COMMENT ON THE INFORMATION PROVIDED BY THE TWO GRAPHS Collision ACollision B