Approximately how much energy (in joules) is contained in one pound of butter?

• A. 1.5 × 10^7 J
• B. 4.2 × 10^8 J
• C. 2.5 × 10^5 J
• D. 3.6 × 10^4 J

Answer: (A)

Verified step by step guidance

1. Understand that the problem is asking for the energy content in one pound of butter, which is typically related to its caloric (food energy) content.
2. Recall that food energy is often given in Calories (with a capital C), where 1 Calorie (kcal) = 4184 joules.
3. Find or estimate the number of Calories in one pound of butter. Butter is mostly fat, and fat contains about 9 Calories per gram. Convert one pound to grams using the conversion: 1 pound = 453.6 grams.
4. Calculate the total Calories in one pound of butter by multiplying the grams by the Calories per gram: Total Calories = 453.6 g × 9 Cal/g.
5. Convert the total Calories to joules by multiplying by 4184 J/Cal: Energy (J) = Total Calories × 4184 J/Cal.