Forces and Motion

Name:

Date:

📚 Part 1: Multiple Choice

1. Which best defines a force?

A measure of how hot or cold an object is

A push or pull that can change the motion of an object

The amount of matter in an object

2. An object moves at constant velocity. Which is true about the forces on it?

Forces are balanced (net force = 0)

Forces are unbalanced and accelerating the object

No forces are acting on the object

3. Which example shows an action–reaction pair (Newton’s 3rd Law)?

A book sitting on a table and gravity acting downwards

A swimmer pushes water backwards and the water pushes the swimmer forwards

Wind blowing a kite so it moves faster

4. Which statement describes Newton’s 2nd Law?

An object remains at rest unless acted on by a net external force

The net force on an object equals mass × acceleration (F = ma)

For every action there is an equal and opposite reaction

✏️ Part 2: Short Answers & Problem Solving

WALT: We are learning to explain balanced and unbalanced forces, identify force pairs, and use F = ma for simple calculations.

Success criteria: I can identify forces in a diagram, say whether forces are balanced, name an action–reaction pair, and calculate net force using F = ma.

Differentiation: Sentence starters are available; use diagrams if helpful. Dyslexia-friendly reading options: short bullet summaries and labelled diagrams provided in class.

Extension: Create a short problem set involving a waka (traditional canoe) with varying mass and wind forces; calculate accelerations for each case.

5. List the main forces acting on a stationary waka tied to a wharf when a steady wind blows from behind it. (3–4 short points)

6. A small motorbike has mass 5.0 kg and accelerates at 2.0 m/s². Calculate the net force. Show your working.

7. A box on a floor has 10 N pushing to the right and 10 N pushing to the left. What is the net force and the acceleration? _________ N, _________ m/s²

8. Explain briefly (one sentence) how the example of someone jumping off a small boat causing the boat to move backward demonstrates Newton’s 3rd Law. Use the terms 'action' and 'reaction'.

9. Exit ticket — Mahi mutunga: Write one thing you learned today and one question you still have.