* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download 10.4 Newton`s Third Law of Motion and Momentum
Uncertainty principle wikipedia , lookup
Coriolis force wikipedia , lookup
Velocity-addition formula wikipedia , lookup
Specific impulse wikipedia , lookup
Quantum vacuum thruster wikipedia , lookup
Modified Newtonian dynamics wikipedia , lookup
Center of mass wikipedia , lookup
Fictitious force wikipedia , lookup
Theoretical and experimental justification for the Schrödinger equation wikipedia , lookup
Laplace–Runge–Lenz vector wikipedia , lookup
Photon polarization wikipedia , lookup
Newton's theorem of revolving orbits wikipedia , lookup
Accretion disk wikipedia , lookup
Centrifugal force wikipedia , lookup
Seismometer wikipedia , lookup
Angular momentum wikipedia , lookup
Angular momentum operator wikipedia , lookup
Classical mechanics wikipedia , lookup
Rigid body dynamics wikipedia , lookup
Centripetal force wikipedia , lookup
Equations of motion wikipedia , lookup
Relativistic mechanics wikipedia , lookup
Classical central-force problem wikipedia , lookup
Newton’s Third Law of Motion Chapter 10, Section 4 Page 393 Objectives for 10.4 State Newton’s third law of motion. Be able to identify the action forces and reaction forces acting on an object. Explain how an object’s momentum is calculated. State the law of conservation of momentum. Use the conservation of momentum to predict the velocity of an object after a collision. Review • Newton’s First Law? • (Inertia) An object at rest will stay at rest, or an object in motion will continue that motion unless acted upon by an outside force. (Inertia – resists a change in velocity) • Newton’s Second Law? • F = ma; acceleration of an object depends on the net force acting on the object and the object’s mass Newton’s Third Law of Motion • If one object exerts a force on another object … …then the second object exerts a force of equal strength in the opposite direction on the first object. Ball Head Action-Reaction Pair • When the dog leaps, it pushes down on the ground (action force) • The ground pushes the dog into the air (reaction force) Action-Reaction Pair Action on the wall motion Reaction on the skater • When a skateboarder pushes against a wall (action force) • The wall pushes the skater in the opposite direction (reaction force) Will there always be movement? • No Normal Force of Earth – Pushing back on the Aardvark The mysterious floating Aardvark Weight – Action Force Pulling toward Earth • The Aardvark’s weight is the action force (normal force) • The normal force of Earth is the reaction force Will the opposite forces cancel? • No, the forces are on different objects • The action force is on the ball • The reaction force is on the wrists Momentum • Momentum is the “quantity of motion” momentum = mass X velocity It is the product of the object’s mass and velocity. A vector quantity: Magnitude and direction Momentum • Momentum can also be referred to as “mass in motion” • The more the mass the more the momentum (an elephant vs. a mouse) • The more the velocity the more the momentum (running vs. walking) Momentum vs. Inertia • Momentum is a measurable vector quantity (product of mass and velocity) • Inertia is dependent on mass, but it is an object’s resistance to a change in velocity What has more momentum: a 200 pound man running at 1 mph or a 65 pound girl running at 4 mph? Why? What has more inertia? Calculating Momentum momentum = mass X velocity • Which has more momentum: a 3.0-kg sledgehammer swung at 1.5 m/s or 4.0-kg sledgehammer swung at 0.9 m/s? • Momentum of first hammer: • Momentum of second hammer: Law of the Conservation of Momentum • The total momentum of any group of objects remains the same, or is conserved, unless outside forces (like friction) act on the objects • activity - Conservation of Momentum