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Week 10 · Keep It Cold

Monday

The keep it cold challenge
// A holder that keeps an ice cube from melting
⏱ about 20 min

Monday: The Keep It Cold Challenge

Rocket sets an ice cube in a cup on the lab table.

By lunch, it is just a puddle.

"Our ice keeps vanishing!" Rocket says. "Let's build an ice saver."

Raven nods. "What do you notice? We need a way to compare."

Nova blinks. "Would you like a hint? A plain cup can be your racer."

The challenge

  • Goal: a holder that keeps an ice cube frozen the longest.
  • Use paper cups, paper napkins, foil, cardboard, tape or an old sock.
  • Every cube is the same size, from the same tray.
  • Every holder sits in the same spot.

A cube to compare with

Put one ice cube in a plain cup with nothing else.

This cube shows how fast ice melts with no help.

If your holder beats the plain cup, it is working!

PLAN THE TEST
  • Read the question.
  • Tap your answer.
Why use ice cubes from the same tray?
One holder sits in a sunny window. Is that fair?
THE PLAIN CUP
  • Read the question.
  • Tap your answer.
Why melt one cube in a plain cup?
Draw two ice holder ideas.

A race with a control

The plain cup is like a racer with no help.

Every holder races against it.

If your cube lasts longer, your holder helped.

If not, you learned something too!

FAIR ICE
  • Read the question.
  • Tap your answer.
Two cubes come from different trays. One is bigger. Is that fair?
Which material may you use?
Your cube lasts longer than the plain cup. What does that tell you?
RuleTrue or false?
Every holder sits in the same spot.?
Cubes can be any size.?
A plain cup races with the holders.?
One holder may sit in the sun.?
WHY THIS EXERCISEKeeping things the same makes the race fair.
Try it
Gather a paper cup, napkins, foil and an old sock.
Feel each one with your fingers.
Which feels thick? Which feels thin?
Safety first
A grown-up handles any scissors.

You planned a fair test!

Tomorrow, we learn why ice melts.