Balanced and unbalanced force worksheet - Free Printable

Let's solve this step by step using the concept of resultant force and Newton’s Third Law of Motion.

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🔍 Key Concepts:

1. Resultant Force: The vector sum of all forces acting on an object.
- If forces are in opposite directions, subtract them (taking direction into account).
- We'll assign:
- Right → positive (+)
- Left → negative (−)

2. Balanced vs Unbalanced Forces:
- Balanced: Net force = 0 → object remains at rest or moves with constant velocity.
- Unbalanced: Net force ≠ 0 → object accelerates.

3. Newton’s Third Law: For every action, there is an equal and opposite reaction.
- However, this law does not cancel forces on the same object — it refers to forces on different objects.
- In this table, we’re analyzing forces on the table, so we don't need to apply Newton’s third law directly here unless asked about reaction forces.
- But note: the forces shown are external forces acting on the table, so we just compute net force.

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We will analyze each row:

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✔ Row 1:

- Forces:
- Right: 750 N
- Left: 500 N
- Resultant = 750 N − 500 N = 250 N to the right
- Since net force ≠ 0 → Unbalanced
- Direction: Right

| Forces | Balanced/Unbalanced | Resultant Force | Direction |
|--------|---------------------|------------------|-----------|
| 500N ←, 750N → | Unbalanced | 250 N | Right |

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✔ Row 2:

- Forces:
- Right: 400 N
- Left: 400 N
- Resultant = 400 N − 400 N = 0 N
- Net force = 0 → Balanced
- No direction (zero force)

| Forces | Balanced/Unbalanced | Resultant Force | Direction |
|--------|---------------------|------------------|-----------|
| 400N ←, 400N → | Balanced | 0 N | — |

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✔ Row 3:

- Forces:
- Right: 300 N
- Left: 500 N
- Resultant = 300 N − 500 N = −200 N → 200 N to the left
- Net force ≠ 0 → Unbalanced
- Direction: Left

| Forces | Balanced/Unbalanced | Resultant Force | Direction |
|--------|---------------------|------------------|-----------|
| 500N ←, 300N → | Unbalanced | 200 N | Left |

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✔ Row 4:

- Forces:
- Right: 500 N
- Left: 500 N
- Resultant = 500 − 500 = 0 N
- Net force = 0 → Balanced
- No direction

| Forces | Balanced/Unbalanced | Resultant Force | Direction |
|--------|---------------------|------------------|-----------|
| 500N ←, 500N → | Balanced | 0 N | — |

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✔ Row 5:

- Forces:
- Right: 1000 N
- Left: 500 N
- Resultant = 1000 N − 500 N = 500 N to the right
- Net force ≠ 0 → Unbalanced
- Direction: Right

| Forces | Balanced/Unbalanced | Resultant Force | Direction |
|--------|---------------------|------------------|-----------|
| 500N ←, 1000N → | Unbalanced | 500 N | Right |

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🟩 Final Table:

| Forces acting on the table | Balanced or unbalanced | Resultant force | Direction of the net force (left or right) |
|----------------------------|------------------------|------------------|--------------------------------------------|
| 500N ←, 750N → | Unbalanced | 250 N | Right |
| 400N ←, 400N → | Balanced | 0 N | — |
| 500N ←, 300N → | Unbalanced | 200 N | Left |
| 500N ←, 500N → | Balanced | 0 N | — |
| 500N ←, 1000N → | Unbalanced | 500 N | Right |

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💡 Note on Newton’s Third Law:

Although the question mentions Newton’s third law, it doesn’t affect the net force on the table because:
- Action-reaction pairs act on different objects.
- For example, if a person pushes the table to the right, the table pushes back on the person to the left — but that reaction force acts on the person, not the table.
- So, only the forces acting on the table are considered here.

✔ Therefore, we focus only on external forces on the table to find the resultant.

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Let me know if you'd like a diagram explanation or real-world examples!