Question 1

How do you convert calories to joules?

Accepted Answer

Multiply calories by 4.184. Example: 100 cal = 418.4 J. For food Calories: 100 Cal = 418.4 kJ.

Question 2

What is a joule?

Accepted Answer

SI unit of energy. 1 J = 1 N⋅m = 1 W⋅s. Lifting 102 grams by 1 meter requires about 1 joule.

Question 3

What's the difference between energy and power?

Accepted Answer

Energy (joules, kWh) is total work done. Power (watts) is energy per unit time. A 100W bulb for 10 hours = 1 kWh of energy.

Question 4

Why are there so many energy units?

Accepted Answer

Different fields developed their own: BTU for heating, calories for nutrition, joules for physics, kWh for electricity billing.

cal to J Converter

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