Worksheet

The four fundamental forces

Grade 11 Science Worksheet - Challenge Me

NameDate

Circle the best answer, or write your answer on the line.

  1. A nucleus of 27 nucleons has radius 1.2 × ∛27 fm. Protons 1 fm apart repel with 230.7 N. What force do two protons on opposite sides feel, to 0.01 N, Ari?

  2. A nucleus of 64 nucleons has radius 1.2 × ∛64 fm. Protons 1 fm apart repel with 230.7 N. What force do two protons on opposite sides feel, to 0.01 N, Bo?

  3. Kira says the strong force must also pull on the Moon. Agree or disagree?

    • Agree: it keeps the Moon in orbit
    • Agree: it is the strongest force
    • Disagree: its range is far too short

  4. Luz says friction isn't a fifth fundamental force; it comes from electromagnetism. Agree or disagree?

    • Agree: it comes from charges in atoms
    • Disagree: it is a fifth fundamental force
    • Disagree: it comes from the weak force

  5. Two protons are 1 fm apart. Which is bigger, the electric push or the gravity pull, Milo?

    • The gravity pull, by about 10³⁶ times
    • The gravity pull, by a little
    • The electric push, by about 10³⁶ times

  6. At 1 fm, the strong pull between two protons beats their electric push. What happens at 3 fm, Noah?

    • Gravity takes over and pulls them in
    • The strong pull grows much stronger
    • The strong pull fades; the push wins

  7. Why can gravity hold a star together when the electric force is far stronger, Pia?

    • Electric forces stop working in space
    • Its charges cancel; its mass doesn't
    • Stars contain no atoms

  8. As the Sun fuses hydrogen, a proton turns into a neutron. Which force allows this change, Ren?

    • The electromagnetic force
    • The weak force
    • Gravity

  9. Why does the Sun use up its hydrogen slowly, over billions of years, Tala?

    • Its first step relies on the weak force
    • Its core is too cold for fusion
    • Gravity stops most of the Sun's reactions

  10. Which force squeezes the Sun's core hot and dense enough for fusion, Zee?

    • Gravity
    • Friction
    • The weak force
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The four fundamental forces

Answer Key - Grade 11 Science Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.

  1. A nucleus of 27 nucleons has radius 1.2 × ∛27 fm. Protons 1 fm apart repel with 230.7 N. What force do two protons on opposite sides feel, to 0.01 N, Ari?

    4.45 N

  2. A nucleus of 64 nucleons has radius 1.2 × ∛64 fm. Protons 1 fm apart repel with 230.7 N. What force do two protons on opposite sides feel, to 0.01 N, Bo?

    2.5 N

  3. Kira says the strong force must also pull on the Moon. Agree or disagree?

    • Agree: it keeps the Moon in orbit
    • Agree: it is the strongest force
    • Disagree: its range is far too short

  4. Luz says friction isn't a fifth fundamental force; it comes from electromagnetism. Agree or disagree?

    • Agree: it comes from charges in atoms
    • Disagree: it is a fifth fundamental force
    • Disagree: it comes from the weak force

  5. Two protons are 1 fm apart. Which is bigger, the electric push or the gravity pull, Milo?

    • The gravity pull, by about 10³⁶ times
    • The gravity pull, by a little
    • The electric push, by about 10³⁶ times

  6. At 1 fm, the strong pull between two protons beats their electric push. What happens at 3 fm, Noah?

    • Gravity takes over and pulls them in
    • The strong pull grows much stronger
    • The strong pull fades; the push wins

  7. Why can gravity hold a star together when the electric force is far stronger, Pia?

    • Electric forces stop working in space
    • Its charges cancel; its mass doesn't
    • Stars contain no atoms

  8. As the Sun fuses hydrogen, a proton turns into a neutron. Which force allows this change, Ren?

    • The electromagnetic force
    • The weak force
    • Gravity

  9. Why does the Sun use up its hydrogen slowly, over billions of years, Tala?

    • Its first step relies on the weak force
    • Its core is too cold for fusion
    • Gravity stops most of the Sun's reactions

  10. Which force squeezes the Sun's core hot and dense enough for fusion, Zee?

    • Gravity
    • Friction
    • The weak force