Howardites

A printable worksheet for the lesson Speed and energy on entry (KS3). It prints on A4 without the website around it. The answers are on a separate sheet for the teacher.

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KS3 · Ages 11 to 14 (Years 7 to 9)Howardites worksheet

Speed and energy on entry

Name:Class:Date:

Key words

Meteoroid
A meteoroid is a small piece of rock or metal travelling through space.
Comet
An icy, dusty object from the outer Solar System that grows a glowing head and tail when it comes near the Sun.
Meteorite
A meteorite is a piece of space rock that has survived its fall through the air and landed on Earth.
Fireball
A fireball is an extra-bright meteor, brighter than the planet Venus.
Ablation
Ablation is the melting and vaporising of a meteoroid's surface as it speeds through the atmosphere.
Fusion crust
Fusion crust is the thin, dark skin that forms on a meteorite as its surface melts during its fall.

Choose the right answer

Circle the letter of the right answer.

  1. About how thick is a meteorite's fusion crust?
    • AAbout ten centimetres
    • BAbout a centimetre
    • CAbout a metre
    • DLess than a millimetre
  2. How does ablation help to keep the inside of a meteorite cold?
    • AIt reflects the heat of the air back into space
    • BIt stops the meteorite moving through the air
    • CThe melted layer is swept off with its heat
    • DIt covers the meteorite with a cold layer of ice
  3. In the particle model, what happens to the particles in the outer layer as the meteoroid heats up?
    • AThey stop moving and lock tightly together
    • BEach particle swells up until the rock bursts
    • CThey vibrate more strongly until the solid melts
    • DThey turn into particles of a new element
  4. A meteoroid catches up with Earth from behind instead of meeting it head on. How does its entry speed compare?
    • ALower, as Earth's motion no longer adds to it
    • BThe same, as direction makes no difference
    • CHigher, as it has been speeding up for longer
    • DHigher, as Earth's gravity pulls harder from behind
  5. What heats the air in front of a meteoroid to thousands of degrees?
    • ASunlight focused by the upper atmosphere
    • BThe meteoroid squashing the air ahead of it
    • CFuel burning inside the meteoroid
    • DLightning in the upper atmosphere

True or false?

Is the answer given right? Tick True or False.

  1. A meteoroid moving at 40 km/s round the Sun meets Earth (30 km/s) head on. Roughly how fast do they approach each other?

    Answer given: About 10 km/s TrueFalse

  2. What would happen if the hot phase of entry lasted for hours instead of a few seconds?

    Answer given: The rock would become a better conductor of heat TrueFalse

Write your answer

Answer in a word or a short sentence.

  1. A meteoroid slows down in the air, yet the total energy is conserved. What does this mean?
  2. Why can no meteoroid enter Earth's atmosphere slower than about 11 km/s?
  3. The fusion crust forms when a molten film becomes solid. What is this change of state called?

Task

Draw an energy transfer diagram for a meteoroid entering the atmosphere. Start with the kinetic store, then show the transfers to the thermal store of the air and rock, and away by light and sound. Add a note explaining why the total energy is conserved even though the meteorite slows down.

Howardites · free to copy for use in your classroom · answers are on the separate teacher's answer sheet