Watt-seconds to Kilocalories conversion

How to convert watt-seconds to kilocalories?

Certainly! To convert energy measured in watt-seconds (joules) to kilocalories, you can use the following relationship:

1 watt-second (or 1 joule) = 0.0002388458966275 kilocalories.

So, to convert 1 watt-second to kilocalories:

$1 \text{ watt-second} \times 0.0002388458966275 \text{ kilocalories/watt-second} = 0.0002388458966275 \text{ kilocalories}$

Real-world examples of watt-seconds:

1. Battery Power: A typical AA battery has a capacity of about 2000 mAh at 1.5 volts. This translates to $2000 \text{ mAh} \times 1.5 \text{ V} = 3000 \text{ mWh}$ Converting to watt-seconds, $3000 \text{ mWh} \times 3600 \text{ seconds/hour} = 10800 \text{ watt-seconds} = 10.8 \text{ kilojoules}$ Converting to kilocalories, $10800 \text{ watt-seconds} \times 0.0002388458966275 = 2.58 \text{ kilocalories}$

2. Light Bulb: A 60-watt light bulb running for one second uses $60 \text{ watt-seconds}.$ Converting to kilocalories, $60 \text{ watt-seconds} \times 0.0002388458966275 = 0.0143307538 \text{ kilocalories}.$

3. Human Energy Expenditure: An adult human burns roughly 2000 kilocalories per day. This is equivalent to: $2000 \text{ kilocalories} / 0.0002388458966275$ $\approx 8.37 \times 10^6 \text{ watt-seconds} \text{ (or joules)}$ $\approx 8.37 \text{ megajoules per day}$

4. Mobile Phone Battery: A smartphone typically uses about 5 watts while actively being used. For one hour of use, $5 \text{ watts} \times 3600 \text{ seconds} = 18000 \text{ watt-seconds}.$ Converting to kilocalories, $18000 \text{ watt-seconds} \times 0.0002388458966275 = 4.299 \text{ kilocalories}.$

These examples show how energy in different contexts, from small batteries to daily human energy expenditure, can be expressed in watt-seconds and converted to kilocalories, giving you a concrete sense of the energy involved.