cal vers erg convertisseur - Calorie vers Erg

Conversion derivation

Express both cal and erg in the same base unit J (joule), then cancel the shared base unit.

1. 1

   Rewrite cal in the base unit

   $$1\mathrm{cal}=4.184\mathrm{J}$$
2. 2

   Rewrite erg in the base unit

   $$1\mathrm{erg}=1\times 10^{-7}\mathrm{J}$$
3. 3

   Forward conversion

   $$\begin{array}{rl}1\mathrm{cal}& =\frac{4.184\cancel{\mathrm{J}}}{1\times 10^{-7}\cancel{\mathrm{J}}}\times 1\mathrm{erg}\\ & =\frac{4.184}{1\times 10^{-7}}\mathrm{erg}\\ & =41,840,000\mathrm{erg}\end{array}$$
4. 4

   Reverse conversion

   $$\begin{array}{rl}1\mathrm{erg}& =\frac{1\times 10^{-7}\cancel{\mathrm{J}}}{4.184\cancel{\mathrm{J}}}\times 1\mathrm{cal}\\ & =\frac{1\times 10^{-7}}{4.184}\mathrm{cal}\\ & =2.39005736\times 10^{-8}\mathrm{cal}\end{array}$$