Prepare for Cold Air!
- Grade Level:
- Upper Elementary: Third Grade through Fifth Grade
- 90 Minutes
- Common Core Standards:
- 3.RI.3, 4.RI.3, 5.RI.3, 6-8.RST.3
- Thinking Skills:
- Applying: Apply an abstract idea in a concrete situation to solve a problem or relate it to a prior experience. Analyzing: Break down a concept or idea into parts and show the relationships among the parts.
Students will observe the difference in heat loss between a well-insulated object and a poorly-insulated object, as well as how to prepare themselves for a winter snowshoe hike. Students will conduct experiments and observe the differences in insulation values for a variety of materials. Students will discover factors that influence winter survival for animals and learn how to dress for an outdoor snowshoe hike at Craters of the Moon.
This lesson can be completed in a variety of ways. With younger students it can be done as a teacher-led activity. Have students write the temperatures on the board as they are observed. Ask them which is warmer or colder.
Older students can work in pairs. Have each pair use a different type of insulation in their experiment. At the end of the activity, have students compare their findings to determine the best and worst insulator.
Other options include:
Repeat the experiment with dampened insulating materials (to model sweat-, rain-,or snow soaked clothing) or with a fan blowing on the samples (to model windy conditions).
Investigate the rate of heat loss when the sample can is immersed in a larger can filled with water and ice cubes to model breaking through an ice-covered stream or lake.
Three Choices for Animals
Winter presents several obstacles to survival: scarce food, deep snow, and cold temperatures are all common at Craters of the Moon. Animals adopt one of three strategies to cope with winter:
Escape through migration
Avoid through hibernation
Adapt to the change in environment.
This lesson focuses on adaptation through added insulation to trap heat.
Staying Warm in Winter
Many animals adapt to cold temperatures by growing a thicker layer of fur. People adapt as well, wearing sweatshirts, heavy coats, boots, and stocking caps when the weather is cold, instead of the T-shirt, shorts, and flip-flops they wear in summer. Heavier fur for animals and extra layers for people both create spaces that trap air. Trapped air provides insulation and slows the rate of heat loss. An animal's fur coat often features hollow hairs, which trap air to provide additional insulation.
Staying warm in winter isn't the only way for animals to survive. Animals that adapt to winter use some or all of the following methods:
· Fat Storage - Deer eat lots in the summer when many shrubs have green, healthy leaves. Their bodies convert the food to fat. The fat helps insulate them from the cold and can be converted back to energy when there is no food to eat.
· Huddling - Small animals, like mice, sleep together with other mice in a communal nest. Heat is shared between
individual animals and not lost to the cold air around them.
· Yarding - Deep snow is difficult to move through for deer and other animals with long legs. When animals yard up they pack the snow down in an area. Packed snow is much easier to walk on because animals use less energy than trying to wade through deep snow.
· Countercurrent heat exchange - Animals with exposed body parts, like a bird's skinny legs, risk heat loss as warm blood travels to these extremities. Heat moves from the outbound arterial supply to the returning vein, warming the returning blood. This exchange of heat helps keep the animal warm.
When People Get Cold
The normal body temperature for a human is 98.6° Fahrenheit (F). Hypothermia occurs when body temperature drops below 98.6°F and can be caused by prolonged exposure to the cold. Symptoms of hypothermia include:
95° - 93°F: Shivering, mild confusion, and muscle incoordination.
93° - 90°F: Shivering, stumbling and slurred speech.
90° - 86°F: All shivering stops, inability to walk, cannot think rationally.
86° - 82°F: Muscles become rigid, semi-consciousness, dilated pupils.
Below 82°F: Total loss of consciousness, eventual death.
If you recognize any of these symptoms in yourself or others when you are out in cold weather, get to a warm place and seek immediate help.
Gather the following materials are needed for each group:
2 clean, empty soup cans of the same size (have students save these a week before the activity)
1 type of material for insulation (suggestions below)
clock or watch
paper and pencil
ruler (to make graphs)
Possible insulating materials: 1 bag cotton balls; old socks (one cotton and one wool for comparison); 1 sq. ft. of quilt batting, polar fleece, or jean denim; or come up with your own.
Do Now: What are some types of insulation you see in your everyday life?
Prepare the cans. Remove labels and rinse out, if necessary. Place one can on the table with the open end down.
Add insulation. Place sock on can or glue cotton balls, quilt batting, or other insulation onto the surface. If using cotton balls, fluff them out once the glue has dried.
Fill the cans with warm water. Try to start with water that is close to normal human body temperature, about 98° to 100°F. Use water from the same container or faucet to fill both cans so the starting temperature is the same for each. Fill each can with an equal amount of water.
Measure the water temperature. Measure and record the initial water temperature without letting the thermometer touch the side of the can.
Place the cans outside. The cans can be placed anywhere (sun, snow, shade, pavement, etc.) as long as both cans are in the same location.
Record the water temperatures for 30 minutes. Measure and record the temperature on the table on page 6 for each can every 5 minutes. Use the graph on the Student Worksheet to show the change in temperature for each can.
7. Answer the questions on the Student Worksheet.
Facilitate a class discussion about the questions on the student worksheet (in Materials):
Did one can cool faster than the other? Why?
If your class used different types of insulation for each can, which one did the best at insulating the can? Why?
- If you had to live outside during winter, what types of clothing would you use to insulate yourself from the cold?
Optional Items for more complex experiments:
Pan or large bowl