Newton's Laws of Motion Vocabulary worksheet with definitions and a pendulum diagram.

Let’s go step by step to match each definition with the correct vocabulary word from Newton’s Laws of Motion.

We’ll look at each numbered clue and think about what it means, then pick the right term from the word bank at the bottom.

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1. Force that opposes motion between two surfaces
→ This is friction. Friction happens when things rub against each other and slows them down.

2. Amount of matter in an object or a measure of the inertia of an object
→ That’s mass. More mass = more stuff in the object = harder to move or stop.

3. Resistance to change
→ This is inertia. Inertia is why you lurch forward when a car stops suddenly — your body wants to keep moving!

4. Speed of an object built in a specific direction
→ That’s velocity. Velocity isn’t just how fast — it’s how fast AND which way.

5. Push or pull
→ Simple! That’s force. You push a door, you pull a wagon — both are forces.

6. Measure of gravitational attraction of one or gravity pulling one object toward the center of another object
→ This is weight. Weight depends on gravity. On the Moon, you’d weigh less because gravity is weaker.

7. Every object persists in its state of rest or uniform motion in a straight line unless it is compelled to change that state by forces impressed on it
→ This is Newton’s First Law (also called the law of inertia).

8. The total of external forces
→ That’s net force. If you push left with 5N and someone pushes right with 3N, net force is 2N to the left.

9. The force equals to objects and causes acceleration if the objects are not balanced by an opposing force
→ This describes Newton’s Second Law: F = ma. Force causes acceleration if unbalanced.

10. Distance traveled per unit time
→ That’s speed. Like “60 miles per hour” — doesn’t say direction, just how fast.

11. Force is equal to the change in momentum (mv) per change in time. For a constant mass, force equals mass times acceleration. F=ma
→ Again, this is Newton’s Second Law. It’s the formula version.

12. For every action, there is an equal and opposite reaction.
→ That’s Newton’s Third Law. When you jump off a boat, the boat moves backward — action/reaction.

13. The rate velocity changes with time
→ That’s acceleration. Speeding up, slowing down, or changing direction — all are acceleration.

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Now let’s write the answers in order:

1. friction
2. mass
3. inertia
4. velocity
5. force
6. weight
7. Newton's First Law
8. net force
9. Newton's Second Law
10. speed
11. Newton's Second Law
12. Newton's Third Law
13. acceleration

Wait — we have “Newton’s Second Law” twice? Let’s check #9 and #11.

Looking again:

- #9 says: “The force equals to objects and causes acceleration...” → still referring to F=ma → Newton’s Second Law.
- #11 gives the actual formula F=ma → also Newton’s Second Law.

But maybe the worksheet expects different terms? Let’s re-read #9 carefully:

> “The force equals to objects and causes acceleration if the objects are not balanced by an opposing force”

Actually, this might be trying to describe unbalanced force, but the phrase “the force equals to objects” is awkward. Probably meant “Force acting on objects causes acceleration...”.

Still, both #9 and #11 point to Newton’s Second Law.

Alternatively, perhaps #9 is meant to be “net force”? But #8 already is “total of external forces” = net force.

Hmm. Let’s compare with standard definitions.

Actually, looking back at the word bank:

Word Bank includes:
- force
- friction
- inertia
- mass
- momentum
- speed
- velocity
- weight
- acceleration
- Newton’s laws (plural)
- Newton’s first law
- Newton’s second law
- Newton’s third law
- net force

So we can use “Newton’s second law” for both #9 and #11? Or maybe #9 is meant to be “unbalanced force”? But “unbalanced force” isn’t in the word bank.

Wait — #9 says: “The force equals to objects and causes acceleration...” — this is poorly worded, but likely refers to Newton’s Second Law.

And #11 explicitly states F=ma — definitely Newton’s Second Law.

But since the worksheet has 13 blanks and 14 words in the bank, maybe repetition is allowed? Or perhaps I misread #9.

Alternative interpretation for #9: “The force [that] equals [mass times acceleration] and causes acceleration...” — still Newton’s Second Law.

Perhaps the intended answer for #9 is “net force”, but #8 is already “total of external forces” = net force.

Let me double-check common textbook phrasing.

Actually, upon second thought, #9 might be describing force itself — but #5 is already “push or pull” = force.

This is tricky. Let’s list all clues again with best matches:

1. friction ✔
2. mass ✔
3. inertia ✔
4. velocity ✔
5. force ✔
6. weight ✔
7. Newton’s First Law ✔
8. net force ✔
9. ??? — “causes acceleration if not balanced” → this is describing what happens when there’s a net force, but #8 is already net force. Alternatively, it could be “Newton’s Second Law” as the principle behind it.
10. speed ✔
11. Newton’s Second Law ✔
12. Newton’s Third Law ✔
13. acceleration ✔

For #9, since it says “the force equals to objects and causes acceleration”, and given that F=ma is Newton’s Second Law, and #11 is the mathematical expression of it, perhaps #9 is meant to be “Newton’s Second Law” too.

Maybe the worksheet allows repeating answers? Or perhaps #9 is “unbalanced force” — but it’s not in the word bank.

Another idea: sometimes “resultant force” is used, but again, not in bank.

Looking at the word bank again — “momentum” is there. Is #9 about momentum?

#9: “The force equals to objects and causes acceleration...” — no, force relates to change in momentum over time, which is actually #11.

#11 says: “Force is equal to the change in momentum (mv) per change in time.” → That’s the impulse-momentum theorem, which is equivalent to F=ma for constant mass.

So #11 is clearly Newton’s Second Law in momentum form.

Then #9 must also be Newton’s Second Law in conceptual form.

I think it’s safe to put “Newton’s Second Law” for both #9 and #11.

Perhaps the worksheet has a typo, but based on content, that’s accurate.

Final matching:

1. friction
2. mass
3. inertia
4. velocity
5. force
6. weight
7. Newton's First Law
8. net force
9. Newton's Second Law
10. speed
11. Newton's Second Law
12. Newton's Third Law
13. acceleration

Yes, this makes sense physically.

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Final Answer:
1. friction
2. mass
3. inertia
4. velocity
5. force
6. weight
7. Newton's First Law
8. net force
9. Newton's Second Law
10. speed
11. Newton's Second Law
12. Newton's Third Law
13. acceleration