Question
(a) The number of kilocalories in food is determined by calorimetry techniques in which the food is burned and the amount of heat transfer is measured. How many kilocalories per gram are there in a 5.00-g peanut if the energy from burning it is transferred to 0.500 kg of water held in a 0.100-kg aluminum cup, causing a $54.9^\circ\textrm{C}$ temperature increase? (b) Compare your answer to labeling information found on a package of peanuts and comment on whether the values are consistent.
1. $5.73 \textrm{ kcal/g}$
Note: at the end of the calculation for part (a) in the video I mistakenly wrote the units for the final answer as $\textrm{kcal/kg}$ but it should be per gram. The units for the final answer to part (a) should be $\textrm{kcal/g}$.
2. According to the peanuts nutrition label in Figure 14.a above, peanuts have $6.1\textrm{ kcal/g}$. This agrees with our calculation to within 1 significant figure.

# OpenStax College Physics for AP® Courses, Chapter 14, Problem 8 (Problems & Exercises)  In order to watch this solution you need to have a subscription.

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