O Levels Physics (5054)•5054/12/M/J/19
Explanation
Power Defined as Rate of Work or Energy Transfer
Steps:
- Recall power is the rate at which work is done or energy is transferred, given by P = W/t or P = ΔE/t.
- Evaluate definition 1: "Energy transferred per second" matches P = ΔE/t directly.
- Evaluate definition 2: "Force × distance moved per second" equals F × (d/t), which is F × v (power in specific cases like constant force), but not the general definition.
- Evaluate definition 3: "Rate of doing work" matches P = W/t exactly; select C as it includes 1 and 3.
Why C is correct:
- Power is fundamentally P = W/t (rate of work) and equivalently P = ΔE/t (energy transfer rate), per physics standards.
Why the others are wrong:
- A includes 2, which is incomplete as it assumes work via force-distance without generality.
- B excludes 3, omitting the core "rate of doing work" definition.
- D excludes 1, ignoring the energy transfer equivalence to work rate.
Final answer: C
Topic: Power
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