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Science Launch G3 / Week 04 / Wednesday
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Week 04 · Magnet Inventions

Wednesday

Build a clip grabber
// Solving problems with magnets
⏱ about 15 min

Wednesday: Build a Clip Grabber

Rocket tapes a magnet to a string and dangles it into the jar. Two clips cling on, then one falls off.

"Almost!" he says. "Let's improve it."

Raven checks the criteria list. "What do you notice? Did it lift three clips?"

Nova hovers by the jar. "Test it three times," she says. "One try is not enough to know."

Your design challenge

Here is the problem. You need to lift paper clips out of a cup. Your hands may not touch them.

  • Criteria: lift at least 3 clips in one try. Do not tip the cup.
  • Constraints: use only the materials below. Build in 15 minutes.
  • One magnet
  • A pencil or craft stick
  • A piece of string, about as long as your arm
  • Tape
  • A cup with 10 steel paper clips inside
  • A few small scraps of aluminum foil in the cup
Safety first
Use one large magnet, like a bar magnet or a big fridge magnet.
A grown-up keeps tiny magnets away from babies and toddlers.
Magnets and paper clips never go in your mouth.
  1. Draw your grabber idea first.
  2. Tape the string to the pencil.
  3. Tape the magnet to the other end of the string.
  4. Lower the magnet into the cup. Lift it slowly.
  5. Count the clips you lifted. Write the number.
  6. Do two more tries. Then change one thing and test again.
MAKE A PREDICTION
  • Read the question.
  • Tap your answer.
Will your grabber lift the aluminum foil scraps?
TryClips liftedMet the criteria? (yes or no)
1
2
3
After my change
How many tries should you test before you decide? Type a number.
WHY THIS EXERCISETesting three times shows whether a design works every time, not just once.

Look at your data

Engineers check every try against the criteria.

Did your grabber lift at least 3 clips? Did the cup stay up?

If one try failed, that is useful. It shows what to change next.

CHECK THE CRITERIA
  • Read the question.
  • Tap your answer.
A grabber lifts 2 clips in one try. Did it meet the criteria?
A grabber lifts 4 clips and the cup stays up. Did it meet the criteria?
StatementTrue or false?
A failed try can help you improve a design.?
Your grabber should lift the foil scraps too.?
WHY THIS EXERCISEFailed tries guide changes, and magnets leave aluminum behind.

Fantastic engineering! Tomorrow we compare designs and make them even better.

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