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Science Launch G4 / Week 06 / Thursday
4/6
Week 06 · Wave Patterns

Thursday

Comparing wave patterns
// Amplitude, wavelength and waves that move things
⏱ about 15 min

Thursday: Comparing wave patterns

Raven rests her hand on the side of a big drum at the community center. A drummer plays softly, then loudly.

"I can feel it buzzing!" Raven says. "And it buzzes more when it is louder."

Rocket puts his hand next to hers. "Whoa. What do you notice when the drummer hits harder?"

Nova keeps her distance from the booming drum. "Here is a clue," she says. "Sound travels in waves too. Think about amplitude."

Amplitude and wavelength in action

Sound travels as waves. Stronger vibrations make a louder sound.

A soft drum beat makes small vibrations. A loud drum beat makes bigger vibrations.

Water waves work in a similar way. A gentle tap makes small ripples. A big splash makes tall waves.

Scientists compare waves by looking for patterns in amplitude and wavelength.

Raven measured four water waves in a pan. Read her data.

WaveAmplitude (height)Wavelength
A1 cm6 cm
B3 cm6 cm
C1 cm12 cm
D2 cm3 cm
Which wave has the biggest amplitude? Write the letter.
Which wave has the longest wavelength? Write the letter.
Statement about Raven's dataTrue or false?
Waves A and B have the same wavelength.?
Waves A and C have the same amplitude.?
Wave D has the longest wavelength.?
WHY THIS EXERCISEWaves can match in one way and differ in another way.
SMALLEST AMPLITUDE TO BIGGEST AMPLITUDE
  • ?Wave B (3 cm)
  • ?Wave A (1 cm)
  • ?Wave D (2 cm)
WHY THIS EXERCISEOrdering by amplitude helps you compare how tall waves are.

Feel the vibrations

Sound is made by vibrations. A drum skin shakes back and forth when it is hit.

A harder hit makes bigger vibrations. Bigger vibrations make a louder sound.

So a loud sound is like a wave with a big amplitude.

LOUD AND SOFT
  • Read the question.
  • Tap your answer.
The drummer hits softly. What kind of vibrations does the drum make?
Which sound comes from stronger vibrations?
Wave C and Wave A have the same amplitude. Which is longer from crest to crest?
SHORTEST WAVELENGTH TO LONGEST
  • ?Wave C (12 cm)
  • ?Wave D (3 cm)
  • ?Wave A (6 cm)
WHY THIS EXERCISEOrdering by wavelength shows which crests are closest together.
How much taller is Wave B than Wave A? Type a number of centimeters.
WHY THIS EXERCISE3 minus 1 is 2, so Wave B is 2 cm taller.
Stronger vibrations make a ____ sound.
Sound travels as ____.
Try it
Rest your fingers gently on the front of your throat.
Hum very softly. Then hum a little louder.
When do you feel more buzzing?

You read wave data like a scientist! Tomorrow we head to the ocean.

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