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 125 nucleons has radius 1.2 × ∛125 fm. Protons 1 fm apart repel with 230.7 N. What force do two protons on opposite sides feel, to 0.01 N, Esme?

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

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

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

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

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

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

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

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

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

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

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

    • Gravity
    • The weak force
    • The electromagnetic force

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

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

  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 125 nucleons has radius 1.2 × ∛125 fm. Protons 1 fm apart repel with 230.7 N. What force do two protons on opposite sides feel, to 0.01 N, Esme?

    1.6 N

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

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

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

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

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

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

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

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

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

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

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

    • Gravity
    • The weak force
    • The electromagnetic force

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

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

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

    • Gravity
    • Friction
    • The weak force