Chapter 2, Problem 84A

Interpretation Introduction

Interpretation:

The liters of milk that should be taken by teenagers per day to meet the recommended amount of Calcium intake needs to be determined.

Concept introduction:

Unit conversion is defined as a multi-step process involving division or multiplication by a numerical factor, rounding and selection of correct number of significant digits. Conversion is factor is the ratio of equivalent value with different units.

Answer to Problem 84A

One liter of milk should be taken by teenagers per day to meet the recommended amount of Calcium intake.

Explanation of Solution

Given Information:

The calcium intake recommended for teenagers is $\text{1300}\text{mg}$ per day. One glass of milk contains $\text{305}\text{mg}$ of calcium (Ca). The volume of one glass of milk is $8$ fluid ounces. Also, one fluid ounces is equal to $\text{29}\text{.6}\text{mL}$.

Calculation: Conversion factor is needed for the calculation of number of liters (L) of milk a teenager should take per day to maintain the calcium level. The conversion factor is as:

$\begin{array}{c}\text{Milk per day}\text{=}\frac{\text{1300 mg Ca}}{\text{1 day}}\text{×}\frac{\text{1 glass}}{\text{305 mg Ca}}\text{×}\frac{\text{8 fluid ounces}}{\text{1 glass}}\text{×}\frac{\text{29}\text{.6 mL}}{\text{1 fluid ounce}}\text{×}\frac{\text{0}\text{.001 L}}{\text{1 mL}}\\ =\text{1 L milk/day}\end{array}$

Hence, one liter of milk should be taken by teenagers per day to meet the recommended amount of Calcium intake.

Conclusion

One liter of milk should be taken by teenagers per day to meet the recommended amount of Calcium intake.