Question

– In a Minute Watch the 1 minute video.


Read the scenarios. Answer the 2 questions below.

1. Residents in Conyers, Georgia, woke up to 27 degrees weather. Ms. Ausby had to let Snoopy outside to go potty. When she opened the patio door, she immediately realized just how cold it was outside. Explain if the cold air from outside entered the house, or if the warm air from inside the house exited. How do you know?

2. Flat Shoals Elementary took their first-grade students to the zoo. The students were studying cold blooded animals. Their first stop was the reptile area. In the reptile exhibit, students noticed that an alligator was lying in the mud in a sunny area. Melissa said that her per turtle lays on his "sun" rock like the alligator. Explain the method of heat transfer that the alligator and the turtle were using to warm their bodies. How do you know?

Answer 1

1) Both happened, but what you feel right away is cold outside air entering.
When Ms. Ausby opened the door, warm indoor air moved toward the colder outside and colder, denser outside air rushed in. Heat always transfers from the warmer place to the cooler place, so the house lost heat while outside air came in. The immediate “cold draft” is caused by the denser cold air flowing into the room (convection), which is why it feels cold right at the doorway.

2) They were mainly using radiation (and also some conduction).
The alligator and the turtle are ectotherms that warm themselves by absorbing the sun’s energy — electromagnetic (infrared/visible) radiation — while basking. Because the turtle is lying on a warm “sun” rock, heat is also transferred directly from the warm rock to the turtle by conduction. You can tell because they are exposing themselves to sunlight and (in the turtle’s case) contacting a warmed surface to gain heat.