Answer: 4%.
- A 2%
- B 4%
- C 6%
- D 8%
Correct answer: B. 4%
Explanation: Area = πr², so the relative error in area is 2 times the relative error in r (power rule for error propagation): 2 × 2% = 4%.
The 7 SI base units. All derived units (newton, joule, watt, volt, etc.) can be expressed as combinations of these 7 fundamental units raised to various powers.
Concept context
SI base units, dimensional analysis, significant figures, and error propagation. The toolkit every physics calculation relies on.