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How People Learn. Conclusion 1: Henri Poincaré. “We must, for example, use language, and our language is necessarily steeped in preconceived ideas. Only they are unconscious preconceived ideas, which are a thousand times the most dangerous of all.”.
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Conclusion 1:Henri Poincaré “We must, for example, use language, and our language is necessarily steeped in preconceived ideas. Only they are unconscious preconceived ideas, which are a thousand times the most dangerous of all.”
“Birds,” said the frog mysteriously. “Birds!” And he told the fish about the birds, who had wings, and two legs, and many many colors.
“Cows,” said the frog. “Cows! They have four legs, horns, eat grass and carry pink bags of milk.”
“And people,” said the frog. “Men, women, children!” And he talked and talked until it was dark in the pond.
Conclusion 2: Expert vs. Novice Learners Conclusion 3: Metacognition or reflection
How Physics Works Model / Theory Observation / Experiment
Ch1-2 Standards of Length Mass and Time Standards M A Force acts on a mass resulting in motion. L,T
Concept Question 1.1 • (2.44 x 10-5) / (2 x 103) = • 2.44 x 10-8 • 2.44 x 10-2 • 1.22 x 10-8 • 1.22 x 102 • 1.22 x 108
Ch1-2 Standards of Length Mass and Time Dimensions of Some Common Physical Quantities
Ch1-3 Dimensional Analysis Concept Question 1.2 Given the following definitions with their dimensions: v = velocity (L/T) a = acceleration (L/T2) t = time (T) Which of the following equations could be correct as far as dimensions are concerned? • v = at2/2 • v = a/2t • v = at • v = a2t/2 • v = a/t2
Ch1-3 Dimensional Analysis How does v depend on a and x? P1.5 (p. 14) Suppose v2 = 2axp What is p?
Ch1-4 Significant Figures Concept Question 1.3 • Which statement is correct regarding significant figures? • 1.355 + 1.2 = 2.555 • 1.478 – 1.3 = 0.18 • 1.513 / 1.5 = 1.009 • 1.5 x 10-3 + 0.1 = 0.1015 • 0.1513 x 1.5 = 0.23
Ch1-4 Significant Figures Do P1.12 (p. 14) P = 2l + 2 w
Ch1-4 Significant Figures Round-off: If next digit is 5, then round up. Scientific Notation: Covered previously.
Ch1-5 Conversion of Units Concept Question 1.4 • How many seconds in a 50 minute class period? • 1000 • 50 • 3 x 10-3 • 4500 • 3 x 103
Ch1-5 Conversion of Units Do P1.24 (p. 15)
Ch1-6 Order-of-Magnitude Calculations CT1.5 A. 500 B. 5,000 C. 50,000 D. 500,000
Who is in 0.1 s of Donovan? A. 2,3,4,5 B. 2,3,4 C. 2,3 D. 2 4 3 5 1 2 CT1.6 Donovan Bailey – Canada – 1996 Olympics
Donavan is roughly 2 meters tall and that gives the scale. Since they covered 100 m in 10 seconds, each meter takes about 0.1 seconds. The answer is c because they are within roughly 1 meter (half Donovan’s height).
I started by assuming a typical person gets a haircut every two months. Next I assumed that a barber could give about 4 haircuts/hr or 20/day or 100/week or 400/month or 800/every two months. I rounded this off to about 500/every two months since there may be times when the barber doesn't have customers. So a barber could take care of about 500 customers and then they would all come back again. There are about 3 million people in Chicago proper and 8 million in the metropolitan area so I picked an average of 5 million to represent Chicago. That means about 5x106 / 500 or 104 or 10,000 barbers. This is just an estimate and may be off by a factor of 10 either way given all the questionable assumptions!
Ch1-7 Scalars and Vectors • A scalar is a pure number. What are some examples? • A vector has magnitude (value) and direction. What are some examples? • The magnitude of a vector could be considered a scalar.
Ch1-8 Problem Solving • Read the problem carefully. • Sketch the system. • Visualize the physical process. • Strategize. • Identify appropriate equations. • Solve the equations. • Check your answer. • Explore limits and special cases.
Ch1-8 Problem Solving Do P1.39 (p. 16) N = number of beats B = beats/second T = time
Mechanics Study of forces and energy and motion. • Force is an agent of change. • Energy is a measure of change.