Waves & Different Materials · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Waves meeting materials

Science · Waves, Light & Sound · ages 12-13
Name ______________________   Date ____________

  1. Sunlight passes straight through a clean glass window. What is this interaction called?

    • Reflection
    • Transmission
    • Absorption

  2. Light bounces straight back off a mirror instead of passing through it. What is this interaction called?

    • Reflection
    • Absorption
    • Transmission

  3. When a material absorbs a wave, some of that wave's energy turns into heat inside the material.

    Circle one:   True   False

  4. Which device relies on infrared waves to work?

    • A TV remote control
    • A radio broadcast tower
    • An X-ray machine at a hospital

  5. A ripe banana looks yellow in sunlight. Which explanation is correct?

    • The banana skin absorbs yellow light and reflects the other colours
    • The banana skin transmits yellow light straight through itself
    • The banana skin reflects yellow light and absorbs the other colours

  6. A white wall reflects 80% of the sunlight hitting it. If the rest is absorbed, what percentage does the wall absorb?

    Reflected80Absorbed20

    Answer: ______________

  7. A wifi signal gets much weaker after passing a room with metal-lined walls. Which interaction is mainly happening at the metal?

    • The metal transmits all of the radio waves through unchanged
    • The metal turns the radio waves into infrared waves
    • The metal reflects most of the radio waves

  8. Priya says a black jacket feels hotter than a white jacket in the sun because black reflects more light. Is she right?

    • Yes, black reflects more light than white
    • No, black absorbs more light than white and turns it into heat
    • No, colour makes no difference to how hot a jacket gets
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Waves meeting materials W1-mt_w5HzPpOUmj-s1

  1. Transmission · Transmission is when a wave passes through a material rather than bouncing off it or being absorbed.
  2. Reflection · Reflection is when a wave bounces off a surface instead of passing through it or being soaked up.
  3. True · Absorbed energy does not just vanish. It gets converted into heat inside the material.
  4. A TV remote control · TV remotes send short infrared pulses to the television. Radio towers use radio waves instead, and hospital X-rays use a different part of the spectrum.
  5. The banana skin reflects yellow light and absorbs the other colours · You see the colour a surface reflects back to your eyes. The banana absorbs the other colours in sunlight and reflects the yellow.
  6. 20 · Reflected and absorbed light must add up to the total, so 100% minus 80% reflected leaves 20% absorbed.
  7. The metal reflects most of the radio waves · Metal surfaces reflect radio waves rather than letting them pass through, which is why wifi signals weaken behind metal walls.
  8. No, black absorbs more light than white and turns it into heat · Dark surfaces absorb most of the light that hits them, so the black jacket heats up more. The white jacket reflects more light away and stays cooler.
Worksheet · LightMySky