Hello.
This, my friends, is a semester long experiment. For the entire semester, I will posting all of my Physics 140 for the University of Michigan notes online.
Keep in mind, this is none of the homework, none of anything except my notes while reading through the text.
CHAPTER 1 – Units, Physical Quantities, and Vectors
 Vectors are used to describe and analyze physical quantities, such as velocity and force, that have direction as well as magnitude.
 Physics = experiment science
 Theory = explanation of natural phenomena based on observation and accepted fundamental principles.
 physics is a process
 Range of validity
 physics process identify relevant concepts, set up problem, execute the solution, evaluate
 model simplified version of a physical system
 good models = simplify a problem enough to make it manageable, yet keeps essential features
 operational definition = some physcial quantities that are so fundamental we can only define them by describing how to measure them.
 unit = standard to compare to
 cesium atom correlation to second
 newton = SI unit of force
 uncertainty = distinction between different measurement
 accuracty = how close to the true value
 fractional error/percent error = percentwise how off your value was from true
LECTURE 1:
 Scalars are just size (magnitude)
 combining scalars is just simple addition
 combining vectors involves taking both direction and magnitude into consideration
 head to tail method: extremely useful, but less accurate
 add the negative of a vector to subtract
 odd thing: two huge vectors added may be 0
 A = magnitude of a vector
 Q: Magnitude of A + B is greater than or equal to AB
 AB is smallest when they are in the same direction
 more precise methods of adding vectors involves using x, y axises
 Vx = Vcosø (x component)
 Vy = Vsinø (ycomponent)
 Unit vector = vector with unit of 1
 unit vector î = x direction
 unit vector ˆj = y direction
 unit vector ˆk = z direction
 A = Axî + Ay ˆj + Azˆk
 Multiplication of Vectors
 multiply by scalar
 dot product and cross product
 matrix multiplication
 not possible to divide vectors
 cA = cA
 Scalar Product = dot product
 A•B=C
 A•B=ABcosø
 This essentially finds the amount of one vector that points in the direction of the other vector
 Tells how parallel the two vectors are
 Cross method needs to be discussed more….
LECTURE 2:
 Overall we are discussing motion in one dimension first
 THIS is much easier since we can express vectors in one dimension as a signed number
 + = right, – = left (or up/down)
 Displacement = distance an object has moved from its starting position
 it is a vector that points from a starting point to an end point
 ∆S = Sf – Si
 Velocity is simply displacement over time
 Speed is the magnitude of the velocity vector
 Instantaneous velocity = V instant = lim (∆t=>0) (∆s/∆t) = ds/dt
 Be sure to examine the relationship between s, v, a
 NOTE: when you take the integral you have no idea what the starting position was or ending position was, you just know the slope of the graph
 Without air resistance, all objects regardless of their mass will fall at the same rate.
 Demoed in class
 Air friction complicates the speed of falling objects

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