Activity 5

Lesson Topic: Physical Sciences: Forces in Nature

Objectives: Antarctica is the windiest continent in the world. Therefore, one of the most important aspects that explorers must understand when planning their journey into the Antarctic is wind speed. If it is too windy, the temperatures outside are extremely cold, and explorers must stay inside to do their research. So, rather than risk their health in the cold temperatures outside, explorers have designed a way to measure wind speed while inside their shelters. This activity will demonstrate how you how to make an indoor wind speed calculator, much like those used by the Antarctic explorers.

NCTM Content Standard Objectives:

  • The Nature of Science
  • Scientific inquiry
  • The scientific world view
  • The Nature of Mathematics
  • The Physical Setting
  • Energy transformations
  • Motion
  • Forces of nature
  • The Nature of Technology

Ohio Science Academic Content Standards: Students demonstrate an understandingof the composition of physical systems and the concepts and principles that describe and predict physical interactions and events in the natural world. In addition, students recognize that science and technology are interconnected, and build skill in the design and construction of scientific technological devices.

Materials you will need:
  • Adult Supervision and Assistance is recommended
/
  • Wire coat hanger; straightened

  • Electrical tape or packing tape
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  • Aluminum foil

  • Medium-sized cardboard box (larger than a shoe box, but smaller than a computer printer box)
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  • Scissors

  • Box cutter or a very sharp knife
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  • Clear tape

  • Wire clipper/cutter
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  • Marker

Instructional Strategies:

1)Take the box and cut off both end flaps, leaving a four-sided tunnel.

2)Use the electrical or packing tape to reinforce the tunnel’s edges so that it feels sturdy:

3)Use the wire clipper to cut the wire coat hanger to make one piece of wire that is 3 inches longer than the width of the open end of the box.

4)Make two holes at one end of the box that are each ½ inch in from the opening and ½ inch below the top of the box. These holes need to be exactly in the same positions on both sides of the box end.

5)Push the wired through the first hole, threading the wire across the opening inside the box and through the second hole on the other side. Then, bend the wire ends down on both sides of the box, making small handles:

6)Cut the aluminum foil to make a curtain and use the long part of the wire inside the opening of the box as a curtain rod. Fold the foil loosely over the rod, but tight enough so that it does not slip off. It should swing freely into the box, about 1 inch above the bottom of the box. Trim the bottom and the sides of the foil so that it fits inside the box opening and can move freely without hitting any of the sides.

7)Using some tape, tape the foil onto the wire at the top. Use more tape around the side of the box opening if you need to, so that the edges are smooth enough to allow the best free movement of the foil curtain.

8)To calibrate the wind box, lightly push the foil in to see how far inside the box it will reach. Mark this point on the side of your box as the end of your wind speed dial. Now, just push the foil half as far as the end speed distance. Make a mark of this point. Now, push the foil half the distance of the half-way point, and mark that distance.

9)Then, connect the distance marks on the side of the box by drawing an arc. Cut out the arc so that the edge of the foil is visible through the sliced out hole.

10) Contact the National Weather Service either by phone, internet, or television to get the current wind speed of the day.

11)Take your box outside into an open area and face the side with the aluminum curtain into the wind. Observe how far into the box the foil curtain moves. Mark this distance on the side of the box. Write the number that corresponds to the wind speed of the day from the National Weather Service on that mark.

12)Perform steps #10-11 on several days that have different wind conditions until you have several different wind speed marks on your arc.

13)Now you can place the box with the aluminum curtain end facing outside an open window that faces west (the most common wind direction for our hemisphere) and read the wind speed of the day from inside a building off your calibration arc! This is how the explorers calculate wind speed from their tents in the Antarctic. You may have to change to a different window in order to be in the direction the wind is coming from.

Beaufort Scale
Wind Force / Wind Observation Description / Wind Speed
MPH / KPH
0 / Smoke rising straight up / >1 / >1.6
2 / Leaves rustling on trees / 4-76 / .5-11
4 / Loose paper pieces are able to blow around / 13-18 / 21-29
6 / Umbrellas that are open are difficult to hold/flip over / 25-31 / 40-50
8 / Walking against the wind is extremely difficult / 39-46 / 63-74
10 / Trees are able to be uprooted / 55-63 / 89-102

**Calm days in Antarctic typically see a wind force between 2-4 on the Beaufort Scale. A day in which explorers/scientists would consider stormy and need to stay inside would begin around a wind force of 8 on the scale, but could be a 6, depending on the other weather conditions, such as temperature and wind (see below). **

In Antarctica, the Wind Chill is an important factor in deciding whether it is ok to work outside or not. What is the Wind Chill Factor? - the wind chill is based on the rate of heat loss from exposed skin caused by the combined effects of wind and cold. As the wind speed increases, heat is carried away from the body at a faster rate, driving down the body temperature. The wind chill temperature, an "apparent" temperature, gives us a better estimate of how cold it really feels outside.