Questions: Complete the following table. Round each of your answers to 3 significant digits. food energy content when eaten ------------ cal kcal kJ three ounces of cooked sirloin steak 2.40 × 10^5 240. 100. an ear of cooked corn 8.5 × 10^4 85.0 an ounce of breakfast corn flakes 460.

Solution Steps

To convert kcal to kJ, we use the conversion factor \(1 \text{ kcal} = 4.184 \text{ kJ}\).

Given: \[ 85.0 \text{ kcal} \]

Calculation: \[ 85.0 \text{ kcal} \times 4.184 \text{ kJ/kcal} = 355.64 \text{ kJ} \]

Rounding to 3 significant digits: \[ 355.64 \approx 356 \]

To convert kJ to kcal, we use the conversion factor \(1 \text{ kJ} = \frac{1}{4.184} \text{ kcal}\).

Given: \[ 460 \text{ kJ} \]

Calculation: \[ 460 \text{ kJ} \times \frac{1 \text{ kcal}}{4.184 \text{ kJ}} = 109.92 \text{ kcal} \]

Rounding to 3 significant digits: \[ 109.92 \approx 110 \]

To convert kcal to cal, we use the conversion factor \(1 \text{ kcal} = 1000 \text{ cal}\).

Given: \[ 110 \text{ kcal} \]

Calculation: \[ 110 \text{ kcal} \times 1000 \text{ cal/kcal} = 110000 \text{ cal} \]

Rounding to 3 significant digits: \[ 110000 \approx 1.10 \times 10^5 \]

Final Answer