Coulomb's law: the force between charges

Grade 11 Science Worksheet - Challenge Me

NameDate

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

  1. Two small spheres carry 40 nC and 40 nC. With k = 8.9875 × 10⁹ N·m²/C², how far apart in cm must they be for a force of 3.6 mN, to the nearest hundredth, Ari?

  2. Two small spheres carry 10 nC and 90 nC. With k = 8.9875 × 10⁹ N·m²/C², how far apart in cm must they be for a force of 0.9 mN, to the nearest hundredth, Bo?

  3. Two small spheres carry 80 nC and 50 nC. With k = 8.9875 × 10⁹ N·m²/C², how far apart in cm must they be for a force of 10 mN, to the nearest hundredth, Esme?

  4. Three equal positive charges sit in a line, 5 cm apart. What is the net force on the middle one, Jun?

    • Twice the force from one neighbor
    • Zero
    • Half the force from one neighbor
  5. A positive charge sits between two equal positive charges, closer to the left one. Which way is the net force on it, Kira?

    • To the left, toward the nearer positive charge
    • To the right, away from the nearer charge
    • Zero, since the charges are equal
  6. Milo says a +10 nC sphere pushes harder on a +2 nC sphere than the +2 nC sphere pushes back. Agree or disagree?

    • Disagree: the two forces are equal
    • Agree: the small one barely pushes
    • Agree: bigger charges push harder
  7. Noah says a charged balloon pulls on a wall harder than the wall pulls on the balloon. Agree or disagree?

    • Disagree: they pull on each other equally
    • Agree: the charged one pulls harder
    • Agree: walls can't pull
  8. Pia says the force between two charges disappears completely once they are 1 m apart. Agree or disagree?

    • Agree: forces stop at 1 m
    • Disagree: it gets weaker but isn't zero
    • Agree: charges can't reach that far
  9. The distance between two charges triples. What fraction of the force is left, Tala?

    • One-ninth
    • One-sixth
    • One-third
  10. One charge triples, and the distance triples. What happens to the force, Zee?

    • It drops to one-third
    • It stays the same
    • It triples
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Coulomb's law: the force between charges

Answer Key - Grade 11 Science Worksheet - Challenge Me

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

  1. Two small spheres carry 40 nC and 40 nC. With k = 8.9875 × 10⁹ N·m²/C², how far apart in cm must they be for a force of 3.6 mN, to the nearest hundredth, Ari?

    6.32 cm
  2. Two small spheres carry 10 nC and 90 nC. With k = 8.9875 × 10⁹ N·m²/C², how far apart in cm must they be for a force of 0.9 mN, to the nearest hundredth, Bo?

    9.48 cm
  3. Two small spheres carry 80 nC and 50 nC. With k = 8.9875 × 10⁹ N·m²/C², how far apart in cm must they be for a force of 10 mN, to the nearest hundredth, Esme?

    6 cm
  4. Three equal positive charges sit in a line, 5 cm apart. What is the net force on the middle one, Jun?

    • Twice the force from one neighbor
    • Zero
    • Half the force from one neighbor
  5. A positive charge sits between two equal positive charges, closer to the left one. Which way is the net force on it, Kira?

    • To the left, toward the nearer positive charge
    • To the right, away from the nearer charge
    • Zero, since the charges are equal
  6. Milo says a +10 nC sphere pushes harder on a +2 nC sphere than the +2 nC sphere pushes back. Agree or disagree?

    • Disagree: the two forces are equal
    • Agree: the small one barely pushes
    • Agree: bigger charges push harder
  7. Noah says a charged balloon pulls on a wall harder than the wall pulls on the balloon. Agree or disagree?

    • Disagree: they pull on each other equally
    • Agree: the charged one pulls harder
    • Agree: walls can't pull
  8. Pia says the force between two charges disappears completely once they are 1 m apart. Agree or disagree?

    • Agree: forces stop at 1 m
    • Disagree: it gets weaker but isn't zero
    • Agree: charges can't reach that far
  9. The distance between two charges triples. What fraction of the force is left, Tala?

    • One-ninth
    • One-sixth
    • One-third
  10. One charge triples, and the distance triples. What happens to the force, Zee?

    • It drops to one-third
    • It stays the same
    • It triples