National Engineering Week is Feb. 21-27! Celebrate all kinds of science with easy experiments the kids will love, then continue the festivities at events later this week.
H20 Music
You’ll Need:
- Five or more drinking glasses or glass bottles
- Water
- Wooden stick such as a pencil
Instructions:
- Line the glasses up next to each other and fill them with different amounts of water. The first should have just a little water while the last should almost full, the ones in between should have slightly more than the last.
- Hit the glass with the least amount of water and observe the sound, then hit the glass with the most water, which makes the higher sound?
- Hit the other glasses and see what noise they make, see if you can get a tune going by hitting the glasses in a certain order.
What’s going on?
Each of the glasses will have a different tone when hit with the pencil, the glass with the most water will have the lowest tone, while the glass with the least water will have the highest. Small vibrations are made when you hit the glass — this creates sound waves that travel through the water. More water means slower vibrations and a deeper tone.
Invisible Ink
You’ll Need
- Half a lemon
- Water
- Spoon
- Bowl
- Cotton bud
- White paper
- Lamp or other light bulb
Instructions:
- Squeeze some lemon juice into the bowl and add a few drops of water.
- Mix the water and lemon juice with the spoon.
- Dip the cotton bud into the mixture and write a message onto the white paper.
- Wait for the juice to dry so it becomes completely invisible.
- When you’re ready to read your secret message or show it to someone else, heat the paper by holding it close to a light bulb.
What's going on?
Lemon juice is an organic substance that oxidizes and turns brown when heated. Diluting the lemon juice in water makes it hard to notice when you apply it the paper — no one will be aware of its presence until it’s heated and the secret message is revealed. Other substances that work in the same way include orange juice, honey, milk, onion juice and vinegar.
Event Alert!
STEAM (science, technology, engineering, art & math) haven Delaware Children's Museum marks the occasion with related events Feb. 23-27. During the Zipline Racers workshop, kids learn potential and kinetic energy while crafting their own speedy contraption. At another activity, use a mechanical toothbrush, nailbrush and some decorations to make your own Bristle Bot.
