Convert an energy of 698 cal to units of joules.
The correct answer and explanation is:
To convert 698 calories (cal) to joules (J), you use the conversion factor:
1 cal = 4.184 J
Step-by-step Conversion:
698 cal×4.184 Jcal=2921.632 J698\ \text{cal} \times 4.184\ \frac{\text{J}}{\text{cal}} = 2921.632\ \text{J}
✅ Final Answer:
698 cal = 2921.63 J
📘 Explanation (300 words):
Energy can be measured in various units, depending on the scientific context. Two of the most commonly used units for energy are calories (cal) and joules (J).
The calorie is often used in chemistry and biology, especially when referring to the energy content of food or energy transfer in chemical reactions. On the other hand, the joule is the SI (International System of Units) unit of energy and is widely used in physics and engineering.
The defined relationship between these units is:
1 calorie = 4.184 joules
This means that one calorie of energy is equivalent to 4.184 joules of energy. So, to convert from calories to joules, you multiply the number of calories by 4.184.
In this specific problem, you are given 698 calories. When you multiply this by 4.184, the result is: 698×4.184=2921.632 joules698 \times 4.184 = 2921.632\ \text{joules}
Rounding to two decimal places (as often done in scientific or lab reporting), the final result is 2921.63 joules.
This conversion is crucial in real-world applications such as:
- Calculating heat energy in calorimetry experiments.
- Determining the energy content of foods.
- Understanding the energy output in combustion or metabolic processes.
By mastering such unit conversions, students and professionals ensure that calculations in scientific disciplines are accurate and standardized across different measurement systems.