Newton's Second Law with Numbers · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Force sets the speeding

Science · Forces & Motion · ages 14-15
Name ______________________   Date ____________

  1. What is a resultant force?

    • The single force left after combining them all
    • The biggest single push, ignoring the rest
    • The mass of the object

  2. Which equation states Newton's second law?

    • F = m / a
    • F = m a
    • F = m + a

  3. Mass, not weight, is what appears in F equals m a.

    Circle one:   True   False

  4. A resultant force of 20 N pushes a 4 kg mass. What is the acceleration in metres per second squared?

    Answer: ______________

  5. A 2 kg mass accelerates at 3 metres per second squared. What is the resultant force in newtons?

    Answer: ______________

  6. A loaded trolley accelerates less than an empty one under the same push. Why?

    • Mass never matters
    • The push grows weaker on heavy loads
    • The same force shifts a bigger mass

  7. Two students solve one problem. One uses the biggest push, the other uses the resultant. Who is right?

    • The biggest push is enough
    • The resultant user, since F = m a needs the total
    • Neither, since forces never combine

  8. A 900 kg car gets 2700 N from the engine while drag takes 900 N. What is its acceleration in metres per second squared?

    Answer: ______________

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Answer key

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

Force sets the speeding W1-mt_Nn2MVJL7bO-s1

  1. The single force left after combining them all · Combine every push and pull first, then calculate.
  2. F = m a · Resultant force equals mass times acceleration.
  3. True · Mass measures resistance to acceleration, so mass goes in the calculation.
  4. 5 · Rearrange to a equals F over m: 20 divided by 4 is 5.
  5. 6 · Force is mass times acceleration: 2 times 3 is 6.
  6. The same force shifts a bigger mass · More mass resists the change, so acceleration falls.
  7. The resultant user, since F = m a needs the total · The law runs on the combined total, not one cherry-picked force.
  8. 2 · The resultant is 1800 N, and 1800 divided by 900 is 2.
Worksheet · LightMySky