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Everyday Machines / Week 06 / Wednesday
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Week 06 · The Light Switch

Wednesday

Look inside a flashlight
// A loop, a gap and a glow
⏱ about 15 min

Wednesday: Look Inside a Flashlight

A grown-up unscrews the flashlight and slides the batteries out.

Rocket peers in. "A spring! A metal strip!"

Raven points at the tiny bulb. "What do you notice it touches?"

Nova glows the path. "Every part must touch the next one."

You need

  • A flashlight that takes AA or smaller batteries
  • A grown-up
  • A towel to set parts on
  • Paper and a pencil
Safety first
A grown-up opens the flashlight and handles the batteries.
AA or smaller batteries only. Never bigger ones.
Batteries and small parts stay away from little kids and mouths.
Do not touch a wall switch, an outlet or a plug.

The look-closely tour

  1. Your grown-up takes the batteries out and sets them on the towel.
  2. Look in the handle. Find the spring or the metal strip.
  3. Look at the bulb. What metal touches it?
  4. Slide the switch. Does anything light? Why not?
  5. Your grown-up puts the batteries back in.
  6. Slide the switch again. Watch the bulb.
For a grown-up
Match the plus and minus marks on the batteries to the case.
Name the parts as the child finds them: spring, strip, bulb, switch.
Screw the flashlight back together yourself.
WHAT HAPPENED?
  • Read the question.
  • Tap your answer.
The batteries are out. You slide the switch. What happens?
The batteries are back in. You slide the switch on. What happens?
Who handles the batteries?

Every part must touch

The metal strip touches the battery.

The battery touches the spring.

The bulb touches the metal too.

One loose part makes a gap. No light.

BUILD THE LOOP
  • Tap a card.
  • Then tap its spot.
1First
2Next
3Then
4Last
SentenceTrue or false?
A spring or strip inside the handle is metal.?
The light works with the batteries out.?
One loose part can make a gap.?
Kids put the batteries in.?
WHY THIS EXERCISEA circuit only works when every part touches the next.
Draw the inside of the flashlight. Label the batteries and the bulb.

You looked inside a real circuit!

Tomorrow, we test it.

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