Misconceptions

#	✗ Wrong Belief	✓ Correct Understanding
1	Dimensional correctness means the equation is physically correct	Dimensional correctness is necessary but not sufficient; KE = $mv^{2}$ is dimensionally correct but physically wrong (missing 1/2)
2	For Z = A/B, error in Z = error in A − error in B	Errors never subtract; $\Delta Z$ /Z = $\Delta A$ /A + $\Delta B$ /B always
3	0.00450 has 5 significant figures	Leading zeros are NOT significant; it has 3 sig figs (4, 5, 0)
4	1500 has 4 significant figures	Without a decimal point, trailing zeros are ambiguous; write as $1.5 \times 10^{3}$ (2 sig figs) or $1.500 \times 10^{3}$ (4 sig figs)
5	Systematic errors cannot be corrected	Systematic errors CAN be identified and corrected by recalibration or adding correction factors
6	Averaging reduces systematic error	Averaging only reduces random error; systematic errors persist regardless of how many readings are taken
7	Dimensional analysis can find the value of 2π in T = 2π√(L/g)	Dimensional analysis cannot determine any dimensionless constant
8	The result of 3.14 × 2.0 should have 3 decimal places	Multiplication uses sig figs, not decimal places; 3.14 (3 sf) × 2.0 (2 sf) = 6.3 (2 sf)
9	Relative error has the same units as the quantity measured	Relative error is always dimensionless (it is a ratio)
10	Random errors always make measurements higher than true value	Random errors are equally likely to be above or below true value — they are unpredictable in direction