For this lesson, students will need the attached worksheets in the resources menu, two frozen water bottles per group, one glove per group, and two digital thermometers per group.
NGSS-3-5-ETS1-3.-Plan and carry out fair tests in which variables are controlledand failure points are considered to identify aspects of a model or prototype that can be improved.
Begin the lesson by building background knowledge and making connections. Ask the students to think back to a time that they were really cold or really hot. Ask them, "what were you doing or where were you that caused you to feel this way? What did you do to cool off or warm up?" Expect answers like, "I put on my jacket or I turned on a fan, etc." Ask the students, "what happens to your body when you are cold? What happens to your body when you are hot?" Expect answers such as you shiver or sweat. Explain to students that as our body heats up, the particles inside of us move faster. When this happens, heat is released through our skin causing us to sweat. The heat leaving our body, causes us to cool off. The opposite occurs when we are cold. The particles slow down, causing us to shiver to regain warmth. Explain to the students, "today we will solve a chilling problem, regarding heating and cooling."
Display the Frozen Snowman video. Have students think-pair-share with their elbow partner. The students will discuss their point of view of the video and what they believe the problem is. As a group, discuss possible ways to preserve a snowman outside for as long as possible without the use of a freezer. Ask the students is it possible at all? Display the Snowman Coat picture. Have the students analyze the picture and ask them, "what is the problem that the students are trying to solve? Discuss this with your partner." Have the students form a hypothesis and share with an elbow partner. Walk around and encourage students to explain their reasoning. Encourage students to ask and answer questions while defining the problem as stated in NGSS 3-5-ETS1-1. Give each student a recording sheet (snowmanblresource sheet)to write down their hypothesis. Allow students to share their predictions.
Explain to students, that today they will be able to investigate to determine if placing a coat on a snowman will melt it or keep it frozen longer. Inform the students that each group will receive two frozen water bottles, which will represent the snowman, a digital thermometer for each, and a glove. Introduce the vocabulary word, "insulator." Explain to students that an insulator is a substance that does not readily allow the passage of heat.
Provide students with the materials to complete the experiment. It is important to instruct the students to not continuously touch the water bottles, as their body heat assists with the melting process. Allow students time to monitor and record the temperatures of each bottle and answer the reflection questions. Be sure to remind the students to keep track of the time they are recording the temperatures. You may provide timers if available.
As students conclude their experiment, allow students an opportunity to share their findings. Discuss as a class, what they discovered from their experiment; was their hypothesis correct? Discuss how their results compared to their original thinking when they were first introduced to the picture. Make a connection back to the students by asking, "how do the results compare to how you feel when you wear your coat?" Ask the students, "what did this investigation teach you about how coat's keep you warm?" Explain to students that the coat is one example of an insulator, however there are many more.
The remaining time is available for cleaning up materials and transitioning to the next lesson.