Question

3.28 a person uses 750 kcal on a long walk. calculate the energy used for the walk in each of the following energy units: a. joules b. kilojoules

Explanation:

Step1: Recall conversion factor

1 kcal = 4184 J

Step2: Convert kcal to joules for part a

$750\ kcal\times4184\ \frac{J}{kcal}=3138000\ J$

Step3: Recall conversion from joules to kilojoules

1 kJ = 1000 J

Step4: Convert joules to kilojoules for part b

$\frac{3138000\ J}{1000}=3138\ kJ$

Answer:

a. 3138000 J
b. 3138 kJ