In the context of energy in food, how many joules (J) are in 55.2 calories (cal), using the conversion $1\mathrm{cal}=4.184J$?

• A. $231J$
• B. $13.2J$
• C. $55.2J$
• D. $924J$

Answer: (A)

Verified step by step guidance

1. Identify the given quantity of energy in calories, which is 55.2 cal.
2. Recall the conversion factor between calories and joules: \$1\ \text{cal} = 4.184\ \text{J}$.
3. Set up the conversion equation to find the energy in joules by multiplying the number of calories by the conversion factor: \(\text{Energy in joules} = 55.2\ \text{cal} \times 4.184\ \text{J/cal}\).
4. Perform the multiplication to calculate the energy in joules (note: do not calculate the final value here, just set up the expression).
5. Interpret the result as the equivalent energy in joules for the given calories.