# Ppt on conservation of momentum law

##### Chapter 3 Energy and Conservation Laws. 2 Conservation laws The most fundamental ideas we have in physics are conservation laws. Statements telling us.

small force for a long time. 12 Conservation of linear momentum The Law of Conservation of Linear Momentum states: The total linear momentum of an isolated system is constant. Isolated implies no external force: 13 Conservation of linear momentum, cont’d This law helps us deal with collisions. If the system’s momentum can not change, the momentum before the collision must equal that after the collision. 14 Conservation of linear momentum, cont’d We can write this as/

##### CONSERVATION OF LINEAR MOMENTUM Chapter 20 Objectives Know that linear momentum is conserved when no outside forces act on the system Know that linear.

). The motorcycle (with rider) has a mass of 350 kg. Calculate and compare the momentum of the car and motorcycle. Conservation of Momentum  The law of conservation of momentum states when a system of interacting objects is not influenced by outside forces (like friction), the total momentum of the system cannot change. If you throw a rock forward from a skateboard, you will move backward in response. Conservation of Momentum Collisions in One Dimension  A collision occurs/

##### Chapter 4 Making Sense of the Universe: Understanding Motion, Energy, and Gravity.

://en.wikipedia.org/wiki/Physical_conservation_la w http://en.wikipedia.org/wiki/Physical_conservation_la w Conservation of Momentum The total momentum of interacting objects cannot change unless an external force is acting on them Interacting objects exchange momentum through equal and opposite forces What is Momentum Really? Momentum is the thing that is conserved (does not change) because the laws of nature (physics) are the same here, there, and over there (space invariant/

##### Physics Midterm Review 2012. Terms - Measurements time elapsed = duration of an event – there is a beginning, a middle, and an end to any event. distance.

+ m s )gd Ballistic Pendulum Momentum conservationenergy conservation mv ob = ( m b + m p )v bp ½ (m b + m p )v bp 2 = (m b + m s )g  y Impulse Change in Momentum Stiff Spring Soft Spring Rubber Bumper Magnetic bumper Force as a function of time graph analysis Rocket Thrust Analysis Newtons Third Law Connection to Change in momentum F t t Impulse = J = F/

is another way to say momentum is conserved! Law of conservation of linear momentum 9-5 Conservation of Linear Momentum © 2014 John Wiley & Sons, Inc. All rights reserved. 9-5 Conservation of Linear Momentum Check components of net external force to determine if you should apply conservation of momentum © 2014 John Wiley & Sons, Inc. All rights reserved. 9-5 Conservation of Linear Momentum Internal forces can change momenta of parts of the system, but cannot change the linear momentum of the entire system/

##### Chapter 9 Linear Momentum and Collisions. Linear Momentum The linear momentum of a particle or an object that can be modeled as a particle of mass m moving.

2f In component form, the total momenta in each direction are independently conserved p ix = p fx p iy = p fy p iz = p fz Conservation of momentum can be applied to systems with any number of particles Conservation of Momentum, Archer Example The archer is standing on a frictionless surface (ice) Approaches: Newton’s Second Law – no, no information about F or a Energy approach – no, no information/

##### 1 WESBURY COLLEGE OF SCIENCE 2013 GR 12 PHYSICAL SCIENCES INTERVENTION FOR SCIENCE LEARNERS SCIENCE DEPARTMENT PROJECT FOUNDATIONS OF LEARNING 2013-09-01.

BE CONSERVED DURING ELASTIC COLLISIONS 47 MECHANICS MOMENTUM VIDEO 48 MECHANICS WESBURY COLLEGE OF SCIENCE LEARNERS MODULE 1 p45-46 p47 p48 AKT 6. VRAE 1-4 49 KNOWLEDLEDGE AREA MECHANICS NEWTON’S SECOND LAW OF MOTION NEWTON’S FIRST LAW OF MOTION GR 11 MECHANICS 50 VIDEO NEWTON’S THREE LAWS OF MOTION 51 NEWTON’S SECOND LAW OF MOTION MATHEMATICAL EXPRESSION OF NEWTON’S SECOND LAW OF MOTION 52 NEWTON’S SECOND LAW OF/

##### Chapter 9 Linear Momentum and Collisions 1. Review of Newton’s Third Law If two objects interact, the force F 12 exerted by object 1 on object is equal.

total momentum of an isolated system equals its initial momentum 8 Conservation of Momentum, 2 Conservation of momentum can be expressed mathematically in various ways In component form, the total momenta in each direction are independently conserved p ix = p fx p iy = p fy p iz = p fz Conservation of momentum can be applied to systems with any number of particles This law is the mathematical representation of the momentum version of the isolated system model 9 Conservation of Momentum/

##### NEW CHAPTER the BIG idea Forces change the motion of objects in predictable ways. Forces Forces change motion. Force and mass determine acceleration. Forces.

KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY Forces transfer momentum. collision conservation of momentum 11.4 CHAPTER RESOURCES CHAPTER RESOURCES VOCABULARY KEY CONCEPT CHAPTER HOME A law stating that the amount of momentum a system of objects has does not change as long as there are no outside forces acting on that system. conservation of momentum KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY Forces transfer momentum. collision conservation of momentum momentum 11.4 CHAPTER RESOURCES CHAPTER RESOURCES VOCABULARY/

##### Chapter 12 Forces and Motion Section 12.2 Newton’s First and Second Laws of Motion Section 12.3 Newton’s Third Law of Motion and Momentum.

the system Key Concept: In a closed system, the loss of momentum of one object equals the gain in momentum of another object—momentum is conserved. Key Concept: In a closed system, the loss of momentum of one object equals the gain in momentum of another object—momentum is conserved. Section 12.3 Newton’s Third Law of Motion and Momentum Law of Conservation of Momentum Law of Conservation of Momentum The total momentum in a group of objects doesn’t change unless outside forces act on the objects/

##### Conservation Theorems: Sect. 2.5 Discussion of conservation of –Linear Momentum –Angular Momentum –Total (Mechanical) Energy Not new Laws! Direct consequences.

a theory to ensure that conservation of energy holds. (e.g., Energy in EM field). Consistent with experimental facts! Conservation Laws & Symmetry Principles (not in text!) In all of physics (not just mechanics) it can be shown: –Each Conservation Law implies an underlying symmetry of the system. –Conversely, each system symmetry implies a Conservation Law: Can show: Translational Symmetry  Linear Momentum Conservation Rotational Symmetry  Angular Momentum Conservation Time Reversal Symmetry  Energy/

##### In the moment t the material volume V(t) contains a given amount of fluid that is described by mass m. The continuity condition states that there is no.

-diagonal members that represent tangential stresses. THE CONSERVATION LAWSmomentum conservation In 2D problems stress tensor has the shape: Writing the Taylor series with the inclusion of only the first member one holds (for x-direction): THE CONSERVATION LAWSmomentum conservation Substitution in Newton second law-axiom (conservation of momentum) for x-direction holds : or in vector form for 3D problem: or by components : THE CONSERVATION LAWSmomentum conservation The main problem is that we have/

##### Chapter 8 Momentum and Collisions. Linear Momentum The linear momentum of a particle or an object that can be modeled as a particle of mass m moving with.

also tells us that the total momentum of an isolated system equals its initial momentum Conservation of Momentum, 2 Conservation of momentum can be expressed mathematically in various ways In component form, the total momenta in each direction are independently conserved Conservation of momentum can be applied to systems with any number of particles Conservation of Momentum, Archer Example The archer is standing on a frictionless surface (ice) Approaches: Newton’s Second Law – no, no information about F/

##### Chapter 11: Energy and its Conservation PHYSICS Principles and Problems.

2 v 1 D.m 1 v 1 2 + m 2 v 2 2 = (m 1 + m 2 )v 3 2 SECTION 1 1.2 Section Check Reason: By the law of conservation of momentum, we know that the total momentum before a collision is equal to the total momentum after a collision. SECTION 1 1.2 Section Check Answer Reason: Before the collision, the car/

##### Momentum The world is filled with objects in motion. Objects have many properties such as color, size, and composition. One important property of an object.

· m/s north Momentum Conservation of Momentum The law of conservation of momentum: –The total momentum of objects that collide is the same before and after the collision. Conservation of Momentum According to the law of conservation of momentum; if one ball swings in then how many balls will swing out? Conservation of Momentum When the cue ball hits another ball, the motion of both balls change. The cue ball slows down and may change direction, so its momentum increases. Conservation of Momentum It seems as/

##### M O MENTUM! Momentum Impulse Conservation of Momentum in 1 Dimension Conservation of Momentum in 2 Dimensions Angular Momentum Torque Moment of Inertia.

m/s 4132.9736 Alternate Solution 5168 40  1500  p Shown are momentum vectors (in g  m/s). The black vector is the total momentum before the collision. Because of conservation of momentum, it is also the total momentum after the collisions. We can use trig to find its magnitude and direction. Law of Sines : 40  sin  1500 Law of Cosines : p 2 = 5168 2 + 1500 2 - 2  5168  1500 cos/

##### Chapter 9 Linear Momentum and Collisions. Momentum Analysis Models Force and acceleration are related by Newton’s second law. When force and acceleration.

acting on the particle.   This is equivalent to Newton’s Second Law.  This is identical in form to the conservation of energy equation.  This is the most general statement of the principle of conservation of momentum and is called the conservation of momentum equation.  This form applies to non-isolated systems.  This is the mathematical statement of the non-isolated system (momentum) model. Section 9.3 More About Impulse Impulse is a vector/

##### Chapter 9 Linear Momentum and Collisions. Momentum Analysis Models Force and acceleration are related by Newton’s second law. When force and acceleration.

acting on the particle.   This is equivalent to Newton’s Second Law.  This is identical in form to the conservation of energy equation.  This is the most general statement of the principle of conservation of momentum and is called the conservation of momentum equation.  This form applies to non-isolated systems.  This is the mathematical statement of the non-isolated system (momentum) model. Section 9.3 More About Impulse Impulse is a vector/

##### Chapter 12 Forces and Motion Section 12.1 Forces Section 12.2 Newton’s First and Second Laws of Motion Section 12.3 Newton’s Third Law of Motion and Momentum.

on the system Law of conservation of momentum-law stating that the total momentum of a system does not change if no net force acts on the system Key Concept: In a closed system, the loss of momentum of one object equals the gain in momentum of another object—momentum is conserved. Key Concept: In a closed system, the loss of momentum of one object equals the gain in momentum of another object—momentum is conserved. Conservation of Momentum Figure 17A and 17B Conservation of Momentum Figure 17C

##### Momentum and Isolated Systems. The previous part of Lesson 2 focused on the Law of Conservation of Momentum. It was stated that...previous part of Lesson.

Systems The previous part of Lesson 2 focused on the Law of Conservation of Momentum. It was stated that...previous part of Lesson 2 For a collision occurring between object 1 and object 2 in an isolated system, the total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision. That is, the momentum lost by object 1 is equal to/

##### Chapter 9 Linear Momentum and Collisions. Linear Momentum The linear momentum of a particle, or an object that can be modeled as a particle, of mass m.

the total momentum of an isolated system equals its initial momentum Conservation of Momentum, 2 Conservation of momentum can be expressed mathematically in various ways In component form, the total momenta in each direction are independently conserved p ix = p fx p iy = p fy p iz = p fz Conservation of momentum can be applied to systems with any number of particles This law is the mathematical representation of the momentum version of the isolated system model Conservation of Momentum, Archer/

##### Sect. 1.2: Mechanics of a System of Particles Generalization to many (N) particle system: –Distinguish External & Internal Forces. –Newton’s 2 nd Law.

example, if N z (e) = 0, L z is conserved. Linear & Angular Momentum Conservation Laws: –Conservation of Linear Momentum holds if internal forces obey the “Weak” Law of Action and Reaction: Only Newton’s 3 rd Law F ji = - F ij is required to hold! –Conservation of Angular Momentum holds if internal forces obey the “Strong” Law of Action and Reaction: Newton’s 3 rd Law F ji = - F ij holds, PLUS the forces must be/

##### 1 Chapter 8 Momentum and Collisions 2 3 8.1 Linear Momentum The linear momentum of a particle or an object that can be modeled as a particle of mass.

that the total momentum of an isolated system equals its initial momentum 9 Conservation of Momentum, 2 Conservation of momentum can be expressed mathematically in various ways In component form, the total momenta in each direction are independently conserved Conservation of momentum can be applied to systems with any number of particles 10 11 12 13 Conservation of Momentum, Archer Example The archer is standing on a frictionless surface (ice) Approaches: Newton’s Second Law – no, no information/

##### Objectives Recall and apply Newton’s three laws of motion Explain Force, Momentum, and conservation of momentum Carry out calculations based on these principles.

Which is Rate of change of momentum. This is a more general statement of Newton’s second law. Conservation of momentum Principle of conservation of momentum: When two or more bodies interact, then the total momentum is conserved if no external forces act on the bodies. This can be derived from Newton’s third law (action/ reaction exerted on different bodies) It is a very important principle! Example – two balls colliding By law of conservation of momentum, momentum before collision is/

##### M O MENTUM! Momentum Impulse Conservation of Momentum in 1 Dimension Conservation of Momentum in 2 Dimensions Angular Momentum Torque Moment of Inertia.

, and the “system” would have to include the table as well. The Cart and The Brick - Part BThe Cart and The Brick - Part B Proof of Conservation of Momentum The proof is based on Newton’s 3 rd Law. Whenever two objects collide (or exert forces on each other from a distance), the forces involved are an action-reaction pair, equal in strength, opposite in/

##### 3 Lecture in physics Newton Laws Keplers laws Friction Rotation Moment Oscillations Waves Deformation Fluid.

and columns the original matrices have (called the "size", "order" or "dimension"), and specifying how the entries of the matrices generate the new matrix.binary operationmatricesNumbersrealcomplex numbersmultipliedelementary arithmetic"size", "order" or "dimension" Momentum conservation One of the most powerful laws in physics is the law of momentum conservation.momentum Collision A collision is an isolated event in which two or more moving bodies (colliding bodies) exert forces on each other/

##### 1 Chapter 9 Linear Momentum and Collisions. 2 Linear Momentum The linear momentum of a particle or an object that can be modeled as a particle of mass.

ix = p fx p iy = p fy p iz = p fz Conservation of momentum can be applied to systems with any number of particles 6 Law of Conservation of Linear Momentum, 2 Whenever two or more particles in an isolated system interact, the total momentum of the system remains constant The momentum of the system is conserved, not necessarily the momentum of an individual particle because other particles in the system may be interacting with it/

##### 1 SACE Stage 2 Physics Momentum in 2-Dimensions. 2 Vector Form of Newton’s Second Law of Motion Consider a particle reflecting off a surface without a.

when no net external forces are applied to a system of two bodies, the total momentum of the system before is the same as the total momentum of the system after. 9 Momentum in 2-Dimensions The Law of Conservation of Momentum Law of conservation of linear momentum If there are no net external forces acting on a system of bodies then the total linear momentum of the system is conserved. NB.(1) No net external forces means an isolated/

##### Momentum Collisions 1 Different kinds of collisions Completely inelastic collision Completely elastic collision Partially elastic collision Explosion.

: collisions, mass, initial velocities Results Next Slide Diagram Calculation Photo Momentum Momentum 1 Conservation of momentum Definition of momentum : Mass  velocity (mv) (vector! Why?) Conservation of total momentum in the experiment Unit : Next Slide Momentum Momentum 2 Conservation of momentum Law of conservation of momentum In a collision the total momentum of the objects before the collision is equal to the total momentum after the collision, provided that there is no external force acting on/

##### SCIENCE 20 RESOURCES Physics Newton’s Laws & Dynamics.

to explain many safety technologies ex. road barriers 3.9 Conservation of Momentum Law of Conservation of Momentum if the net force acting on a system is zero, the sum of the momentum before an interaction equals the momentum after the interaction Summomentum Since p = mv, mv can be substituted for p Action Reaction How does Newton’s Third Law apply to conservation of momentum?  each action has an opposite and equal reaction Forces act/

##### 1 Condensed Matter Physics J. Ellis (10 Lectures) Periodic Systems: Overview of crystal structures, the reciprocal lattice. Phonons: Phonons as normal.

a crystal – space is no longer uniform but has a new symmetry – its periodic, so the law of conservation of momentum is replaced by a new law – the conservation of ‘crystal momentum’ in which momentum is conserved to within a factor of ħG. E.g. Diffraction: wavevector allowed to change by factors of G Phonon creation: Adding a G vector to a phonon’s wavevector does not change its properties, but its crystal/

##### 12.2 Newton’s First and Second Laws of Motion Inertia is the tendency of an object to resist a change in its motion. Objects in motion tend to stay in.

of Momentum 12.2 Newton’s First and Second Laws of Motion In each collision, the total momentum of the train cars does not change—momentum is conserved. Conservation of Momentum 12.2 Newton’s First and Second Laws of Motion In each collision, the total momentum of the train cars does not change—momentum is conserved. Conservation of Momentum 12.2 Newton’s First and Second Laws of Motion In each collision, the total momentum of the train cars does not change—momentum is conserved. Conservation of Momentum/

##### 12.3 Newton’s Third Law of Motion and Momentum 4. A 25-N force accelerates a boy in a wheelchair at 0.5 m/s2. What is the mass of the boy and the wheelchair?

the law of conservation of momentum, if no net force acts on a system, then the total momentum of the system does not change. Conservation of Momentum 12.3 Newton’s Third Law of Motion and Momentum In each collision, the total momentum of the train cars does not change—momentum is conserved. Conservation of Momentum 12.3 Newton’s Third Law of Motion and Momentum In each collision, the total momentum of the train cars does not change—momentum is conserved. Conservation of Momentum 12.3 Newton’s Third Law of/

##### Rotation. Introduction  A well-thrown football follows a projectile path while spinning around its long axis.  The motion of the football is easy to.

usually starts out slowly and then gets faster and faster.  This may appear to be a violation of the law of conservation of angular momentum but is in fact a beautiful example of its validity. Conservation of Angular Momentum  Angular momentum is the product of the rotational inertia and the rotational speed and, in the absence of a net torque, remains constant.  Therefore, if the rotational inertia decreases, the rotational speed must increase/

##### Chapter 9 Linear Momentum and Collisions. Momentum Analysis Models Force and acceleration are related by Newton’s second law. When force and acceleration.

acting on the particle.   This is equivalent to Newton’s Second Law.  This is identical in form to the conservation of energy equation.  This is the most general statement of the principle of conservation of momentum and is called the conservation of momentum equation.  This form applies to non-isolated systems.  This is the mathematical statement of the non-isolated system (momentum) model. Section 9.3 More About Impulse Impulse is a vector/

##### PHY 151: Lecture 9A 9.1 Linear Momentum 9.2 Isolated System (Momentum) 9.3 Nonisolated System (Momentum) 9.4 Collisions in One Dimension.

new force acting on the particle – –This is equivalent to Newton’s Second Law –This is identical in form to the conservation of energy equation –This is the most general statement of the principle of conservation of momentum and is called the conservation of momentum equation This form applies to non-isolated systems –This is the mathematical statement of the non- isolated system More About Impulse Impulse is a vector quantity The/

momentum Section 2 Conservation of Momentum Chapter 6 Momentum is Conserved The Law of Conservation of Momentum: The total momentum of all objects interacting with one another remains constant regardless of the nature of the forces between the objects. m1v1,i + m2v2,i = m1v1,f + m2v2,f total initial momentum = total final momentum Conservation of Momentum Section 2 Conservation of Momentum Chapter 6 Conservation of Momentum Chapter 6 Sample Problem Conservation of Momentum Section 2 Conservation of Momentum/

##### Chapter 2 Newton’s Laws of Motion

m2 u2 m1 v1 m2 v2 Principle of conservation of momentum The momentum of m1 time of action m1.u1 m1v1 time m1 u1 m2 u2 m1 v1 m2 v2 Principle of conservation of momentum The momentum of m2 time of action m2.v2 m2.u2 time m1 u1 m2 u2 m1 v1 m2 v2 Principle of conservation of momentum For N bodies in collision. Without external force, sum of momenta before = sum of momenta after Collisions in 2-dimension/

##### Work, Energy, Power, Momentum

energy from the agent doing the work Lecture 9 Spring 2008 4/23/2008 Energy is Conserved! The total energy (in all forms) in a “closed” system remains constant This is one of nature’s “conservation lawsConservation applies to: Energy (includes mass via E = mc2) Momentum Angular Momentum Electric Charge Conservation laws are fundamental in physics, and stem from symmetries in our space and time Emmy Noether formulated/

##### Chapter 7 Linear and angular momentum.

with an initial velocity v1. The mass collides with a 5-kg mass m2, which is initially at rest. Find the final velocity of the masses after the collision if it is perfectly inelastic. According to the Law of Conservation of Momentum example An archer stands at rest on frictionless ice and fires a 0.5-kg arrow horizontally at 50.0 m/s. The combined/

##### Thurs Nov 21 Forces Test Asst: Guided Notes pages

ALSO equal zero. If delta p equals zero for a system, then momentum is CONSERVED. You must be able to describe the RECOIL EFFECT in BOTH of the following ways: By Newton’s third law, if spacecraft pushes gasses out backwards, gasses push spacecraft forwards. (3 points) By conservation of momentum, say… Total initial momentum equals zero; momentum of gasses one way + spacecraft other way (which are equal and opposite/

##### D-Theory - Model of cell-structured space

root, and we get mv = constant. The speed changed to relative quantity, which has now a direction. Thus the conservation law of momentum in three-dimensional space can be united to the conservation law of absolute momentum at low relative speeds. For the moving bodies there exists only one single law of conservation. Lets write m² c² = constant for a body, which moves at absolute speed c in relation to rest/

##### MOMENTUM & COLLISIONS.

same. The equation you see here states this fact mathematically. The vector sum of the momenta of all the objects at an initial time equals the total momentum at any later (final) time. Conservation of momentum The law of conservation of momentum can be derived from Newton’s 2nd and 3rd laws Newton’s 2nd law  F = ma Newton’s 3rd law  Forces are equal but opposite * Refer to Kinetic Books- 8.7 For/

##### Review Chap. 8 Momentum, Impulse, and Collisions

y directions After Before Conservation of Momentum External force Internal forces Isolated system: External force = 0 Newton’s 2nd law Newton’s 3rd law You can add these forces to obtain the net (internal) force for the system The sum of these forces cannot be applied to a single object. Conservation of Momentum Total momentum of an isolated system is conserved. Total momentum Momentum conservation gives a vector equation. Note that momentum conservation is valid for an/

##### UCSD Physics 10 Momentum & Impulse. UCSD Physics 10 Winter 20062 Momentum, p The linear momentum p of an object is the product of the object’s mass m.

1 + m 2 Δv 2 = 0 Conservation of Linear Momentum.Conservation of Linear Momentum. UCSD Physics 10 Winter 20066 Linear Momentum Often misused word, though most have the right ideaOften misused word, though most have the right idea Momentum, denoted p, is mass times velocityMomentum, denoted /!!! –Newton’s 3 rd Law of Motion! Which Canoe experience the greater acceleration?Which Canoe experience the greater acceleration? How do the momenta of each canoe compare?How do the momenta of each canoe compare? –Be /

this experiment. Conservation of Momentum - - Newton’s Third Law Conservation of Momentum Law of the Conservation of Momentum (mass in motion): The total momentum is conserved (or does not change) for any group of objects, unless outside forces (such as friction) act on the objects. Relationship between Momentum, Mass, & Velocity What causes an object’s momentum to increase? How does velocity affect momentum? How does mass affect momentum? Momentum = m x v Calculating Momentum - Newton’s Third Law Which has/

##### Lesson 1 Gravity and Friction Lesson 2 Newton’s First Law

is zero, neither its velocity nor its momentum change. Because momentum is the product of mass and velocity, the force on an object equals its change in momentum. Lesson 4-4 Conservation of Momentum According to the law of conservation of momentum, the total momentum of a group of objects stays the same unless outside forces such as friction act on the objects. What is the law of conservation of momentum? Lesson 4-5 Conservation of Momentum (cont.) When colliding objects bounce off/

##### Lesson 1 Gravity and Friction Lesson 2 Newton’s First Law

is zero, neither its velocity nor its momentum change. Because momentum is the product of mass and velocity, the force on an object equals its change in momentum. Lesson 4-4 Conservation of Momentum According to the law of conservation of momentum, the total momentum of a group of objects stays the same unless outside forces such as friction act on the objects. What is the law of conservation of momentum? Lesson 4-5 Conservation of Momentum (cont.) When colliding objects bounce off/

##### Making Sense of the Universe Understanding Motion, Energy, and Gravity.

–3. For every force there is an equal and opposite reaction force Conservation Laws in Astronomy Our goals for learning: Why do objects move at constant velocity if no force acts on them? What keeps a planet rotating and orbiting the Sun? Where do objects get their energy? Conservation of Momentum The total momentum of interacting objects cannot change unless an external force is acting on them/

##### EXPERIMENTAL EVIDENCES FOR PARTICLE-LIKE PROPERTIES OF WAVES

-production must not violate some very fundamental laws in physics: Charge conservation, total linear momentum, total relativistic energy are to be obeyed in the process Due to kinematical consideration (energy and linear momentum conservations) pair production cannot occur in empty space Must occur in the proximity of a nucleus Will see this in an example Energy threshold Due to conservation of relativistic energy, pair production can only occur/