cal vers MJ convertisseur - Calorie vers Megajoule

Conversion derivation

Express both cal and MJ 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 MJ in the base unit

   $$1\mathrm{MJ}=1,000,000\mathrm{J}$$
3. 3

   Forward conversion

   $$\begin{array}{rl}1\mathrm{cal}& =\frac{4.184\cancel{\mathrm{J}}}{1,000,000\cancel{\mathrm{J}}}\times 1\mathrm{MJ}\\ & =\frac{4.184}{1,000,000}\mathrm{MJ}\\ & =0.000004184\mathrm{MJ}\end{array}$$
4. 4

   Reverse conversion

   $$\begin{array}{rl}1\mathrm{MJ}& =\frac{1,000,000\cancel{\mathrm{J}}}{4.184\cancel{\mathrm{J}}}\times 1\mathrm{cal}\\ & =\frac{1,000,000}{4.184}\mathrm{cal}\\ & =239,005.736138\mathrm{cal}\end{array}$$