Chapter 10, Problem 64A

Interpretation Introduction

Interpretation: The time required to reduce one pound of fat needs to be determined.

Concept Introduction: Energy is the capacity to do any work. Energy can be of any form and can be transferred from one to another.

Answer to Problem 64A

8.7 hours.

Explanation of Solution

The following conversions can be used to solve the problem:

  $\text{1 gram=7}\text{.7 kcal}$

And,

  $\text{1 pound}\text{=}\text{454 grams}$

Therefore,

  $\text{7}\text{.7 kcal × 454 = 3495}\text{.8 kcal}$

So, 3495.8 kcal is used to burn 1 pound.

Now, at speed 4 mph for one hour 400 kcal is consumed.

So, dividing the total amount of calories in 1 pound by 400 kcal, one can find the time required to burn 1 pound,

  $\frac{3495.8}{400} =\text{ 8}\text{.7 hours}$ .

So, 8.7 hours of walk is needed to burn 1 pound of fat.

Conclusion

Thus, 8.7 hours of walk is needed to burn 1 pound of fat.