joules 和 calories 有什么区别？ A joule (J) is the SI unit of energy, while a calorie (cal) is a traditional unit. 1 calorie = 4.184 joules. In nutrition, "Calories" (with capital C) are actually kilocalories (kcal): 1 Cal = 1,000 cal = 4,184 J.
如何将 kWh 转换为 joules？ One kilowatt-hour (kWh) equals 3,600,000 joules or 3.6 megajoules (MJ). The formula is: kWh × 3,600,000 = joules. For example, 1 kWh = 3.6 MJ. This is commonly used for electricity billing.
什么是 BTU，何时使用？ BTU (British Thermal Unit) is the energy needed to raise 1 pound of water by 1°F. 1 BTU = 1,055 joules. It's commonly used in the US for heating, cooling, and air conditioning system ratings (e.g., "12,000 BTU air conditioner").
一千瓦时中包含多少 calories？ 1 kilowatt-hour 等于 860,421 calories (cal) 或 860.421 kilocalories (kcal/Cal)。该转换有时用于将电能与食物能量或代谢产出进行比较。
什么是 electron-volt (eV)？ An electron-volt is a tiny unit of energy used in particle physics: 1 eV = 1.602 × 10⁻¹⁹ joules. It's the energy gained by an electron moving through 1 volt of electric potential. Common in atomic and nuclear physics.