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Everyday Machines / Week 05 / Thursday
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Week 05 · The Toilet

Thursday

Test for a secret leak
// A tank, a flap, a float and gravity
⏱ about 15 min

Thursday: Test for a Secret Leak

"My toilet whispers at night," Rocket says. "Is it leaking?"

Raven holds up a little bottle of food coloring.

"What do you notice if the color moves?" she asks.

Nova sets a timer. "Ten minutes. Watch and wait."

The secret leak

An old flapper can let water sneak into the bowl.

You cannot see this leak. The water is clear.

Color in the tank shows where the water goes.

A worn flapper can waste thousands of gallons a year.

  • Food coloring
  • A timer or a clock
  • A grown-up
  • Paper and a pencil
Safety first
A grown-up lifts the lid and adds the coloring.
Hands stay out of the tank and the bowl.
Nothing goes in your mouth.
Wash your hands with soap after the test.

The dye test

  1. Your grown-up puts a few drops of coloring in the tank.
  2. Do not flush. Start the timer for ten minutes.
  3. Look at the water in the bowl. Is it still clear?
  4. After ten minutes, look again.
  5. Write what you see in the table.
  6. Flush right away so the tank does not stain.
TimeBowl water color
Start
After ten minutes
For a grown-up
Color in the bowl before any flush means the flapper leaks.
Flush right after the test to clear the color.

The refill time

  1. Flush the toilet.
  2. Count the seconds until the hiss stops.
  3. Write the number in your table.
  4. Flush again and count one more time.
TrySeconds to refill
One
Two
WHAT HAPPENED?
  • Read the question.
  • Tap your answer.
Color shows in the bowl before a flush. What does it mean?
The bowl stays clear after ten minutes. What does it mean?
Why flush right after the test?
SentenceTrue or false?
A worn flapper can leak water into the bowl.?
You can always see a flapper leak.?
A grown-up adds the coloring.?
Two tries make a fairer test than one.?
WHY THIS EXERCISEA simple test can find a leak you cannot see.
Draw the tank and bowl. Show where the color went.

You tested a toilet like a plumber!

Tomorrow, you explain the whole flush.

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