Physical quantities — common mistakes

Always check for dimensional homogeneity in your derivations and problem-solving. It's an excellent way to spot errors before you've even finished the calculation!

Remember to express uncertainties to one significant figure, and ensure your final answer's precision matches the uncertainty's decimal places.

SI units (International System of Units) provide a globally standardised system for measurements, ensuring consistency and clarity in scientific communication and calculations across different countries and disciplines.

Yes, a vector quantity can have zero magnitude. For example, if an object has zero velocity, its velocity vector has a magnitude of zero. Similarly, if forces are balanced, the resultant force vector is zero.

Absolute uncertainty is the raw error value with its units (e.g., ±0.05 m), indicating the range of possible values. Percentage uncertainty expresses this error as a fraction of the measured value (e.g., 2%), useful for comparing precision or combining uncertainties in multiplication/division.