Single correct option
Which one of the following is the correct expression of the SI unit of power in terms of base units?
- A. kg m² s⁻²
- B. kg m s⁻²
- C. kg m² s⁻³
- D. kg m s⁻³
Show answer and solution
Answer: (C) kg m² s⁻³
Power is work done per unit time. Work (energy) has the unit joule = kg m² s⁻², so power = J/s = kg m² s⁻³ (watt). The option kg m² s⁻² is the unit of energy itself, kg m s⁻² is the newton (force), and kg m s⁻³ is not a standard unit. Always divide energy by time to get power.
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