What 2 units measure energy ?
http://en.wikipedia.org/wiki/Units_of_energy
The two units that measure energy are joules (J) and calories (cal). To understand how to calculate and convert energy, you need to understand the relationship between these units.
1. Joule (J): The joule is the standard unit of energy in the International System of Units (SI). It represents the amount of energy transferred when a force of one newton is applied over a distance of one meter. To calculate energy in joules, you can use the formula: Energy = Force × Distance. For example, if you apply a force of 10 newtons over a distance of 5 meters, the energy would be 10 J × 5 m = 50 J.
2. Calorie (cal): The calorie is a non-SI unit of energy commonly used in nutrition. It represents the amount of energy required to raise the temperature of one gram of water by one degree Celsius. The calorie is often used to measure the energy content of food. There are actually two types of calories:
- Small calorie (cal): Also known as the gram-calorie, it is equal to 1/1000th of a kilocalorie.
- Kilocalorie (kcal): Commonly referred to as just "calorie" in the context of food energy. It is equal to 1000 small calories.
To convert between joules and calories, you can use the conversion factor:
1 cal ≈ 4.184 J (approximation)
So, if you have a value in joules, you can divide it by 4.184 to convert it into calories, and vice versa.
For example, to convert 1000 joules to calories:
1000 J ÷ 4.184 ≈ 238.85 cal
Similarly, to convert 500 calories to joules:
500 cal × 4.184 ≈ 2092 J
These conversions may be useful when working with energy in different contexts or calculation requirements.