Step 1: Definition of Power in Physics
Power in physics quantifies the rate of work completion or energy transfer. It indicates the speed at which work is performed. The governing equation for power is:
\[
\text{Power} = \frac{\text{Work}}{\text{Time}} = \frac{\text{Force} \times \text{Distance}}{\text{Time}}
\]
Consequently, power directly reflects the rapidity of work execution or energy expenditure. Step 2: Analysis of Options
- (A) Speed: This is the correct choice, as power is intrinsically linked to the speed or rate of work performance.
- (B) Time: While time is a component in power calculations, it is not the direct measure of power itself.
- (C) Weight: Weight is a force but lacks a direct relationship with power.
- (D) Capacity: Capacity denotes the potential to perform work, but power does not directly quantify this. Step 3: Conclusion
Therefore, power indicates the speed at which work is accomplished.