Ch8 Impulse-Momentum What is momentum? Equation Newton’s Laws Sports Politics Physics Equation Newton’s Laws Newton’s 2nd Law – a different story System Center of mass

What is the secret to the egg toss? Ch8 Impulse What is the secret to the egg toss?

Ch8 Impulse What is the secret to the egg toss? Impulse J Collisions Complex Average vs. instantaneous forces Time Graphs Momentum

Conservation of Momentum Ch8 Conservation of Momentum Newton’s Laws – Momentum 1st – merry-go-round 2nd – block down a ramp 3rd – rock falling to earth When is momentum conserved? How is it conserved? Falling rock Sand dropped in box car In terms of forces In terms of momentum, different systems

Lab 5 Always record uncertainty and units Never say “human error” Write clearly Be quantitative: avoid “not very accurate,” “really close” Show/explain work/calculations Use full sentences Attach separate pages to ensure you have a full report, i.e. discussion of error, diagram, further questions, difficult procedures, etc. In other classes lab write-ups are more precise

Ch8 Collisions Newton’s Cradle Collisions Perspective of Forces 1 stationary, 1 moving Both moving Bounce – Elastic Stick – Inelastic Multiple dimensions Many-bodies Opposite of a collision? Center of Mass KE lost Perspective of Forces

Ch8 Problems Examples – Collisions Physical situation Representation Conceptual – System, Before/After, Conservative? Visual – Drawing, Coordinate System Mathematical – Set up equations, vectors require components in independent directions Solution Interpretation Units Limiting cases Reasonableness