功率：瓦特与每秒能量
Power: watts and energy per second
把功率定义为能量传递的速率（功率 = 能量 ÷ 时间，单位是瓦特），并比较不同日常情境下的能量传递速率。
Define power as the rate of energy transfer (power = energy ÷ time, measured in watts), and compare energy transfer rates in different everyday contexts
学习证据 / Evidence
- 说出功率的定义及其单位（瓦特）。
- 运用 P = E/t，在已知其中两个量的情况下计算功率、能量或时间。
- 比较常见电器的额定功率，并解释额定功率的含义。
- 解释为什么功率更大的电器能以更快的速度完成同样的工作，但会消耗更多能量。
- States the definition of power and gives its unit (watt)
- Uses P = E/t to calculate power, energy, or time given the other two quantities
- Compares the power ratings of common appliances and explains what the rating means
- Explains why a higher-powered device does the same job faster but uses more energy
评估问题 / Assessment
如果{{name}}正在比较一个100瓦的灯泡和一个10瓦的LED灯，他们能解释这两个数字的含义，并计算出每个灯在一小时内消耗多少能量吗？
If {{name}} was comparing a 100 W light bulb with a 10 W LED, could they explain what those numbers mean and calculate how much energy each uses in an hour?