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4th grade · Science · Unit 2 of 8

Waves & Codes

Waves, amplitude, wavelength and sending patterns.

What your child practices

Practices how waves have amplitude and wavelength and can make objects move, and how patterns like codes, flashes and digital signals carry information.

Arizona Academic Standards learning standard: 4.P4U1.1 · waves that carry energy from place to place without the objects touching

How we explain it

Children can open this short lesson before they practice.

  1. Waves have high points (crests) and low points (troughs).
  2. Amplitude is a wave's height. Bigger waves carry more energy.
  3. Wavelength is the distance from one crest to the next.
  4. Patterns like Morse code or digital code can send information.

Example: Which ocean wave has more energy: one 1 m tall or one 3 m tall? The taller wave has a bigger amplitude. Bigger amplitude means more energy. Answer: the 3 m wave

Waves & Codes in Arizona

In the Arizona Academic Standards, this is unit 2 of 8 in 4th grade Science, after Energy, Speed & Collisions and before Circuits at Work.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: Arizona Department of Education

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    The distance from one wave top to the next is the…

    • depth
    • amplitude
    • volume
    • wavelength

  2. Question 2

    Which sends information using light patterns?

    • A doorbell
    • A traffic light
    • A whistle
    • A drum

  3. Question 3

    Waves made by dropping a pebble in a pond spread…

    • straight up
    • outward in circles
    • into the pebble
    • nowhere

  4. Question 4

    A barcode is a pattern of…

    • sounds
    • smells
    • lines
    • tastes

  5. Question 5

    Which uses a pattern to send information?

    • A pillow
    • Morse code
    • A sandwich
    • A puddle

  6. Question 6

    A wave tank has waves with a bigger amplitude. A toy boat will…

    • stay still
    • bob higher
    • move less
    • sink at once

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