Foundations of Scientific Inquiry and Physics
Foundations of Scientific Inquiry and Physics
This domain tests how physics knowledge is built and communicated: the cycle of observation, hypothesis, experiment, and revision; the difference between hypothesis, theory, and law; SI units and dimensional analysis; measurement uncertainty and significant figures; and the interpretation of graphs and models. The exam favors questions that ask you to evaluate an experimental design or judge whether a conclusion follows from data.
Core rules and concepts
- A hypothesis is a testable prediction; a theory is a broad, well-supported explanatory framework; a law describes a regularity, often mathematically. No hierarchy of proof turns a theory into a law.
- SI base units include meter, kilogram, second, ampere, kelvin, mole, and candela. Derived units must reduce to these.
- Dimensional analysis can verify an equation's form but cannot supply dimensionless constants.
- Report uncertainty to one significant figure and match the decimal place of the reported value; keep guard digits during calculation.
- Random error scatters repeated measurements and affects precision; systematic error shifts all readings and affects accuracy.
Worked example
A student measures a metal cylinder's mass as 54.2 g and volume as 8.0 cm³. Density is 54.2/8.0 = 6.775 g/cm³. The volume has two significant figures, so report 6.8 g/cm³. If the balance was not zeroed, the error is systematic: it shifts every mass reading, so repeated trials will cluster but around the wrong value.
Traps that cost marks
Confusing accuracy with precision; keeping too many digits in a final answer; treating a theory as just a guess; and ignoring unit conversions before substituting into a formula. On graph questions, check axis labels and units before reading a slope.