Solving Problems Using Dimensional Analysis



Solving Problems Using Dimensional Analysis









Terms Used in Dimensional Analysis

Dimensional analysis is a problem-solving method that can be used whenever two quantities are directly proportional to each other and one quantity must be converted to the other by using a common equivalent, conversion factor, or conversion relation. All medication dosage calculation problems can be solved by dimensional analysis.

It is important to understand the following four terms that provide the basis for dimensional analysis.



  • Given quantity: the beginning point of the problem


  • Wanted quantity: the answer to the problem


  • Unit path: the series of conversions necessary to achieve the answer to the problem


  • Conversion factors: equivalents necessary to convert between systems of measurement and to allow unwanted units to be canceled from the problem

    Each conversion factor is a ratio of units that equals 1.

Dimensional analysis also uses the same terms as fractions: numerators and denominators.



  • Numerator = the top portion of the problem


  • Denominator = the bottom portion of the problem

Some problems will have a given quantity and a wanted quantity that contain only numerators. Other problems will have a given quantity and a wanted quantity that contain both a numerator and a denominator. This chapter contains only problems with numerators as the given quantity and the wanted quantity.

Once the beginning point in the problem is identified, then a series of conversions necessary to achieve the answer is established that leads to the problem’s solution.

Below is an example of the model that is used in solving problems by the dimensional analysis method. It also demonstrates the correct placement of the basic terms that are used in this method.




image


The Five Steps of Dimensional Analysis

Once the given quantity is identified, the unit path leading to the wanted quantity is established. The problem-solving method of dimensional analysis uses the following five steps.

Jul 5, 2016 | Posted by in PHARMACY | Comments Off on Solving Problems Using Dimensional Analysis

Full access? Get Clinical Tree

Get Clinical Tree app for offline access