Lesson Plans Procedures for Using the Science Lesson Plans Glaciers Arctic vs. Antarctic Food Webs Insulation Penguins Cupcake Core Sampling Wind Chill Ozone Hole Plate Tectonics

# Wind Chill

## Objectives

Students will define wind chill.

Students will make a graph of the data they collect.

## Standards Assessed

Earth Science

3-5 Benchmark

D. Analyze weather and changes that occur over a period of time.

Earth Systems / Y2003.CSC.S01.G03-05.BD.L04.I04

04. Describe weather by measurable quantities such as temperature, wind direction, wind speed, precipitation and barometric pressure.

Earth Systems / Y2003.CSC.S01.G03-05.BD.L04.I03

03. Investigate how water changes from one state to another (e.g., freezing, melting, condensation and evaporation).

6-8 Benchmark

C. Describe interactions of matter and energy throughout the lithosphere, hydrosphere and atmosphere (e.g., water cycle, weather and pollution).

Earth Systems / Y2003.CSC.S01.G06-08.BC.L07.I03

03. Describe the water cycle and explain the transfer of energy between the atmosphere and hydrosphere.

## Materials

• Shallow pan

• Water

• Thermometer

• Fan

• Board or chart paper for graph.

## Procedure

1. Discuss the concept of wind chill. Do students feel colder when the wind is blowing? Is there a way they can find out what the wind chill is on a given day? (News shows and Web sites listed below)

2. Have the students find whether movement of the air or wind affects the temperature that we feel.

3. Prepare a pan of water with about .5 inch of room temperature water. Lay a thermometer in the water with the ball of the thermometer submerged. Take the temperature at the time you put the water in and then again five minutes later.

4. Have the students make a hypothesis of what they think will happen.

5. Put a fan by the water so that the air from the fan blows over the water. Wait about 20 minutes and again check the temperature. (Be careful! Don't get the fan or the cord of the fan wet!)

6. Plot the points on a graph on the board.

7. Students will write a summary of the graph and then answer the questions, “How does moving air or wind affect the temperature of the water? What do you think you could do to stay warm?”

8. Have students go to http://www.nws.noaa.gov/om/windchill to see the chart of wind chill factor (or the teacher could print the chart and distribute to students).

## Evaluation

Points Criteria

 0, 5, 10 Heading, Title, Problem and Hypothesis are listed. 0, 5, 10 Materials and procedure are explained. 0, 10, 20 Data points were included and defined. 0, 10, 30, 50 A clear conclusion that explains the results of the procedure is given. 0, 5, 10 Mechanics (grammar, spelling, punctuation, etc.)

## Enrichment

Older students might want to calculate the wind chill factor using the information below.

 Formula to calculate a Fahrenheit wind chill. T(wc) = .0817 √3.71V0.5 + 5.81 -0.25V)(T - 91.4) + 91.4

T(wc)    Wind Chill

V            Wind Speed in statute miles per hour

T             Temperature in degrees Fahrenheit

Note: When wind speeds are below four miles per hour, the above formulas will give you a wind chill that is higher than the actual temperature. When wind velocities are near zero and you are standing still, your body heat warms the air near your body. This warm air near your body provides some insulation from the colder environment. As a result, it may feel warmer than the actual temperature.

Source for both formulas: The National Weather Service
http://www.5cities.com/weather/wind_chill_formula.htm

## Extra-credit

Students can determine from a wind chill graph when it would be dangerous to be outdoors.

Source for the formula: The National Weather Service