Let's go through the questions step by step and explain the solutions.
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Q.2: Use the words in the box to complete sentences about Newton's first law of motion.
Words in the box:
- unbalanced force
- in motion
- at rest
- balanced force
Now, let’s analyze each part:
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a) An object at rest tends to stay _at rest_.
✔ Correct answer: at rest
Explanation:
Newton's First Law of Motion (also known as the Law of Inertia) states that an object at rest will remain at rest unless acted upon by an unbalanced force. So, if nothing is pushing or pulling it, a stationary object stays still.
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b) An object in motion tends to stay _in motion_.
✔ Correct answer: in motion
Explanation:
Similarly, an object moving at a constant velocity (speed and direction) will continue to do so unless an unbalanced force acts on it. This is why seatbelts are important — without them, your body keeps moving forward during a sudden stop.
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c) An object acted upon by _balanced force_ stays at rest.
✔ Correct answer: balanced force
Explanation:
When forces on an object are balanced (equal in magnitude and opposite in direction), there is no net force, so the object does not accelerate. If it was at rest, it remains at rest. For example, two people pushing a box with equal force in opposite directions — the box doesn’t move.
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d) An object acted upon by _unbalanced force_ changes speed and direction.
✔ Correct answer: unbalanced force
Explanation:
An unbalanced force means the net force is not zero. This causes acceleration — a change in speed, direction, or both. For instance, when one person pushes the box harder than the other, it starts moving.
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✔ Summary of Q.2:
| Sentence | Correct Answer |
|--------|----------------|
| a) | at rest |
| b) | in motion |
| c) | balanced force |
| d) | unbalanced force |
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Q.3: Which of the following terms is defined as the tendency of objects to resist changes in their state of motion?
Options:
a) Speed
b) Inertia
c) Force
d) Mass
✔ Correct answer: b) Inertia
Explanation:
Inertia is the property of matter that causes it to resist changes in its state of motion. It is directly related to mass — the greater the mass, the greater the inertia.
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Speed (a): How fast something is moving — not resistance to change.
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Force (c): A push or pull that can cause a change in motion.
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Mass (d): A measure of how much matter is in an object; it *relates* to inertia but isn't the definition itself.
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Inertia (b): The actual term for the resistance to change in motion.
👉 So,
inertia is the correct choice.
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✔ Final Answers:
Q.2:
a) at rest
b) in motion
c) balanced force
d) unbalanced force
Q.3: b) Inertia
Let me know if you'd like a diagram or real-life examples!
Parent Tip: Review the logic above to help your child master the concept of newton laws worksheet high school.
