PHYS 2521: General Physics I - Introduction: Physics and Measurements

Flashcards covering lecture topics including course objectives, nature of science, scientific method, uncertainties, significant figures, SI units, unit conversions, and dimensional analysis.

What are the primary course objectives for PHYS 2521: General Physics I?

To understand fundamental concepts of Newtonian mechanics, see physics in the surrounding world, develop natural intuition and curiosity, prioritize conceptual understanding and modeling over just plugging numbers into equations, and explore quantitative models, mathematical tools, and problem-solving skills.

What are the office hours and office location for Dr. Bijay Shrestha in PHYS 2521?

Office: SSB 207; Office hours: Monday and Wednesday from 8:00 AM to 12:30 PM, and Thursday from 1:00 PM to 3:00 PM.

Which textbooks and reference materials are listed for PHYS 2521?

Textbook: College Physics 2e by OpenStax (Chapters 1-12). Reference: Physics 5e by James Walker (Chapters 1-15).

How did Isaac Asimov define physics?

"Physics is the basic science. One can easily argue that all other sciences are specialized aspects of physics."

What are the six steps of the Scientific Method presented in the lecture?

1. Observation (notice and describe phenomena in nature), 2. Hypothesis (propose an explanation), 3. Prediction (make testable predictions), 4. Experimentation (design and conduct experiments), 5. Analysis (analyze data and draw conclusions), and 6. Theory (develop into a theory if supported by evidence).

How are a Model, a Theory, and a Law defined in physics?

A Model is a simplified representation of reality used to understand complex phenomena. A Theory is a well-substantiated explanation supported by extensive evidence. A Law is a statement that describes what happens, often expressed mathematically.

How is the total percent uncertainty calculated when combining multiple measurements?

The total percent uncertainty is obtained by adding the percent uncertainties from all individual measurements: Total % Uncertainty = % Unc1 + % Unc2 + % Unc3 + …

What is the difference between accuracy and precision?

Accuracy refers to the closeness of a measured value to a standard or known value. Precision refers to the closeness of two or more measurements to each other.

What is the rule for significant figures in multiplication and division calculations?

The result can have no more significant figures than the number in the calculation with the fewest significant figures (e.g., $3.2 \times 5.63 = 18$).

What is the rule for significant figures in addition and subtraction calculations?

The result is determined by the number with the largest uncertainty, meaning it has the fewest digits in the decimal point (e.g., $3.26 + 4.3 = 7.6$).

How many significant figures are in the numbers $0.003141$ and $31415.000$?

$0.003141$ has 4 significant figures (zeros at the front are not counted). $31415.000$ has 8 significant figures (zeros after non-zero numbers are counted).

What historical incident is cited to show why units matter, and what was its cost?

The Mars Climate Orbiter was lost in 1999 due to a unit conversion error between metric and English units, costing $125 million.

What are the seven fundamental SI units and their corresponding physical quantities?

Length: meters ($\text{m}$), Mass: kilograms ($\text{kg}$), Time: seconds ($\text{s}$), Temperature: Kelvin ($\text{K}$), Current: Ampere ($\text{A}$), Luminosity: candela ($\text{cd}$), and Amount of substance: mole ($\text{mol}$).

What are the metric prefixes, symbols, and powers of 10 for giga, mega, kilo, milli, micro, and nano?

Giga (G): $10^9$, Mega (M): $10^6$, Kilo (k): $10^3$, Milli (m): $10^{-3}$, Micro ($\mu$): $10^{-6}$, Nano (n): $10^{-9}$.

What are the conversion factors given for inches to centimeters, cubic meters to liters, miles to kilometers, and kilograms to pounds?

$1$\text{ inch} = 2.54$\text{ cm}$, $1$\text{ m}^3 = 1000$\text{ liter}$, $1$\text{ mile} = 1.609$\text{ km}$, and $1$\text{ kg} = 2.20462$\text{ pound}$.

What is $100$\text{ km/hr}$converted to$\text{m/s}$and$\text{mph}$$?

$100$\text{ km/hr} = 27.778$\text{ m/s} = 62.15$\text{ mph}$$.

What is $10$\text{ m}^3$converted to$\text{cm}^3$$ and liters?

$10$\text{ m}^3 = 10000000$\text{ cm}^3 = 10000$\text{ liter}$$.

What is $100$\text{ N}$converted to$\text{g\,cm/s}^2$$?

$100$\text{ N} = 10000000$\text{ g\,cm/s}^2$.

What are the base unit dimensions for Position, Force, Velocity, and Acceleration?

Position: $[x] = [\text{L}]$, Force: $[F] = \text{MLT}^{-2}$, Velocity: $[v] = \text{LT}^{-1}$, Acceleration: $[a] = \text{LT}^{-2}$.

How is dimensional analysis used to verify the equation $x = v_0 t + \frac{1}{2} a t^2$?

Left Hand Side dimension: $[\text{L}]$. Right Hand Side dimensions: $[\text{LT}^{-1}][\text{T}] + [\text{LT}^{-2}][\text{T}]^2 = [\text{L}] + [\text{L}] = [\text{L}]$. Since both sides evaluate to $[\text{L}]$, the equation is dimensionally consistent.