Science Teaching Series

Internet Resources

I. Developing Scientific Literacy

II. Developing Scientific Reasoning

III. Developing Scientific Understanding

IV. Developing Scientific Problem Solving

V. Developing Scientific Research Skills

VI. Resources for Teaching Science

Dimensional Analysis - Sample Problems

See text for solutions

Example 1 – Medicine 

The label on a stock drug container gives the concentration of a solution as 1200mg/ mL.  Determine the volume of the medication that must be given to fill a physician’s order of 1600 mg of the drug (figure 17.8).


Example 2 – Space Science

On June 19, 1976, the United States successfully landed Viking1 on the surface of the planet Mars.  Twenty years later, on July 4, 1997, NASA landed another robotic probe named the Mars Pathfinder at a distance of 520 miles from the Viking 1 landing site.  Unlike the Viking mission, the Pathfinder mission included a surface rover known as Sojourner, a six-wheeled vehicle that was controlled by an Earth-based operator. Knowing that the distance between the landing site of the Mars Pathfinder and the Viking 1 craft is 520 miles, what would be the minimum number of hours required to drive Sojourner to the Viking site assuming a top speed of 0.70 centimeters per second, and no obstacles (figure 17.9).


Example 3 - Physics

A 2.00-L tank of helium gas contains 1.785 g at a pressure of 202 kPa.  What is the temperature of the gas in the tank in kelvin given that the molecular weight of helium is 4.002 g/mol and the universal gas constant is 8.29 x 103 L·Pa/mol·K (figure 17.10)?


Example 4 - Chemistry

Calculate the mass of silver metal that can be deposited if a 5.12 ampere current is passed through a silver nitrate solution for 2.00 hours.  Note: there are 96,500 C per mole of electrons, and the gram atomic weight of silver is 107.9g/mol (figure 17.11).


Example 5 – Earth Science

The island of Greenland is approximately 840,000 mi2, 85 percent of which is covered by ice with an average thickness of 1500 meters. Estimate the mass of the ice in Greenland in kg (assume two significant figures). The density of ice is 0.917 g/mL, and 1 cm3 = 1 mL (figure 17.12).


Example 6 - Biology

The rate of photosynthesis is often measured in the number of micromoles of CO2 fixed per square meter of leaf tissue, per second (µmol CO2/m2s).   What is the rate of photosynthesis in a leaf with an area of 10 cm2 if it assimilates 0.00005 grams of carbon dioxide each minute (MW of CO2= 48 g/mol)? (figure 17.13).