# Physics 321 Physics 321 Hour 1a Course Introduction Course Components

Course Outline Prerequisites: ODEs, Mathematica

Reading: Due before lecture HW: Due MWF - see schedule on Learning Suite Take-home Tests: Due every other Thursday Midterm Exams: In the Testing Center Final Exam: In Class Course Components

Homework: 15% Take-home Tests: 45% Midterms (2): 20% Final: 10% HW & Takehome Tests Physics 321

Hour 1b Newtons Laws of Motion Before Newton What is the natural motion of an object? Greeks without force, motion stops Kepler straight lines (earthheavens)

Galileo circles (heavens earth) Descartes matter and motion are conserved Before Newton How do we understand collisions? Descartes conservation of motion Huygens motion = mass x velocity Leibniz vis viva = mass x velocity2

Newtons 0th Law The quantity of motion is the measure of the same, arising from the velocity and quantity of matter conjointly. = Huygens definition of motion Newtons 1st Law

Every body continues in its state of rest, or of uniform motion in a right line, unless it is compelled to change that state by forces impressed upon it. = Descartes idea of natural motion Newtons 2nd Law The change of motion is proportional to the

motive force impressed, and is made in the direction of the right line in which that force acts. = A way to measure/define force Newtons 3rd Law To every action there is always an equal reaction; or, the mutual actions of two bodies

upon each other are always equal, and directed to contrary parts. Forces are binary Momentum is conserved instant by instant Forces add as vectors Newtons Laws and Measurement

What do we have to measure to verify/apply Newtons laws of motion? What is mass, space, time? How have our ideas of mass, space and time changed since 1687? Do Newtons Laws Work? How could we tell if forces are really are binary?

Are they binary? Two examples: charges and a bat, Lorentz force What would be necessary for forces to be conserved instant by instant?