1 Calorie : energy needed to heat 1 g of water by 1oC 1 Calorie = 4.182 Joules ≈ 4.200 J1 C (or food calorie or KILO calorie) = 4200J

BTU (British Thermal Unit)

Energy needed to heat 1 lb of water by 1oF…

1 BTU = 1055 Joules ≈ 1 kiloJ

Guess: how much energy is there in a pound of an explosive, such as dynamite or TNT, compared to, say, a pound of chocolate chip cookies?

Object Energy in one gram Compared to TNT Calories          Joules

Bullet(moving at speed of sound) 0.01 40 0.015Battery (flashlight) 0.01  40 0.015Battery (computer) 0.1 400 0.15TNT (trinitrotoluene) 0.651 2723 1Modern High Explosive (PETN) 1  1.6Chocolate Chip Cookies 5 21 kJ 8Butter 7 29 kJ 11Gasoline 10 42 kJ 15Methane gas (CH4) 13 54 kJ 20Hydrogen gas (H2) for fuel cell 26 110 kJ 40Asteroid or meteor (30 km/sec) 107 450 kJ 165Uranium-235 20 million Ca l84 billion J 30 million  

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