Question

an average person expends about 845 kilojoules of energy per hour of walking. suppose a person eats 2 baked potatoes with butter, each having 37 grams of carbohydrates and 4.3 grams of protein from the potato and 4 grams of fat from the butter. how many hours of walking will it take for the person to expend the energy from the two potatoes?

• round to the nearest half - hour.
• do not include units in your answer.

provide your answer below:

Explanation:

Step1: Calculate energy from carbohydrates

Energy from carbohydrates: Each gram of carbohydrate provides 17 kJ.
For 2 potatoes, total carbohydrate grams = \(2\times37 = 74\) grams.
Energy from carbs \(E_{carbs}=74\times17=\ 1258\) kJ.

Step2: Calculate energy from protein

Energy from protein: Each gram of protein provides 17 kJ.
For 2 potatoes, total protein grams = \(2\times4.3 = 8.6\) grams.
Energy from protein \(E_{protein}=8.6\times17 = 146.2\) kJ.

Step3: Calculate energy from fat

Energy from fat: Each gram of fat provides 38 kJ.
For 2 potatoes (butter part), total fat grams = \(2\times4=8\) grams.
Energy from fat \(E_{fat}=8\times38 = 304\) kJ.

Step4: Calculate total energy

Total energy \(E = E_{carbs}+E_{protein}+E_{fat}=1258 + 146.2+304=1708.2\) kJ.

Step5: Calculate number of walking hours

Number of hours \(h=\frac{1708.2}{845}\approx2.02\). Rounding to the nearest half - hour gives 2.

Answer:

2