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Everyday Machines / Week 08 / Thursday
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Week 08 · The Refrigerator

Thursday

Test the seal and read a thermometer
// A machine that moves heat out
⏱ about 15 min

Thursday: Test the Seal and Read a Thermometer

Rocket holds a strip of paper. "Let us test the seal!"

Raven shuts the door on the paper and tugs it gently.

"What do you notice? Does it slide or does it hold?"

Nova points at a thermometer. "Hint: numbers can tell us about heat too."

Test one: the paper strip

A tight seal grips a strip of paper.

Test the top, one side and the bottom.

We change one thing: the spot on the seal.

Same paper, same door, same gentle tug.

  • A strip of paper
  • A thermometer a grown-up approves
  • A fridge
  • A grown-up to help
Safety first
A grown-up stands with you at the fridge.
Open the door only for a moment each time.
Never touch the back of the fridge or its coils.
Never unplug the fridge.
Nothing is eaten during this lesson.
  1. Lay the paper strip across the seal.
  2. Close the door on it. Tug gently.
  3. Does it slide out or hold? Mark it.
  4. Try a second spot and a third spot.
SpotSlides out or holds?
Top
Side
Bottom

Test two: read the thermometer

A thermometer measures how warm or cold something is.

Fridge air should be 40 degrees or colder.

Room air is much warmer than that.

  1. A grown-up puts the thermometer in the fridge.
  2. Close the door and wait ten minutes.
  3. Open the door and read the number fast.
  4. Close the door. Now read the room thermometer.
PlaceReading
Inside the fridge
In the room
WHAT HAPPENED?
  • Read the question.
  • Tap your answer.
The paper slides out easily at one spot. What does that show?
Which reading should be lower?
What one thing changed in the paper test?
SentenceTrue or false?
A tight seal grips a strip of paper.?
Fridge air should be 40 degrees or colder.?
The room is colder than the fridge.?
We leave the fridge door open while we wait.?
WHY THIS EXERCISEA test gives a result you can write down and compare.
THERMOMETER SENSE
  • Read the question.
  • Tap your answer.
Why wait ten minutes before reading the fridge thermometer?
Why read the number fast?
Who puts the thermometer in the fridge?
Draw the two thermometers. Mark the fridge one with a snowflake.

You tested a seal and read a thermometer!

Tomorrow, you explain how a fridge works.

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