Task
Show what you know about forces! For each situation you will draw force arrows, decide if the forces are balanced forces or unbalanced forces, and say whether each force is a contact force or a force that acts at a distance.
Situation 1 — A book resting on a table
1a. Draw the two force arrows acting on the book (gravity pulling down; the table pushing up).
1b. Are the forces balanced or unbalanced? How do you know?
Situation 2 — Kicking a soccer ball across the grass
2a. Name the force that slows the ball down as it rolls, and say whether it is a contact force or a force at a distance.
2b. While the ball is slowing down, are the forces balanced or unbalanced? Explain.
Situation 3 — Two magnets
3. Two magnets pull towards each other without touching. Name this force and say whether it is a contact force or a force at a distance.
Situation 4 — A tug-of-war
4a. Draw force arrows so that the forces are unbalanced and the left team wins.
4b. Explain what happens to the rope and why, using the words unbalanced forces.
Situation 5 — Show what you know
5. Sort these forces into the table: friction, gravity, a push, magnetism, a pull.
| Contact force | Force at a distance |
|---|---|
Rubric criteria (weights as a percentage of this assessment)
| Criterion | Weight | Descriptor |
|---|---|---|
| Balanced and unbalanced forces | 30% | High (5–6): Correctly identifies balanced vs unbalanced forces in every situation and justifies each from the object's movement. Sound (3–4): Correctly identifies balanced vs unbalanced in most situations with some justification. Limited (1–2): Identifies balanced or unbalanced in a simple case with little justification. |
| Representing forces with arrows | 30% | High (5–6): Draws clear, correctly directed and labelled force arrows, using arrow size to show the size of each force. Sound (3–4): Draws labelled force arrows in the correct directions. Limited (1–2): Draws arrows with some errors in direction or labelling. |
| Contact and non-contact forces | 25% | High (5–6): Correctly classifies all forces as contact or at-a-distance and correctly names the forces involved (friction, gravity, magnetism). Sound (3–4): Correctly classifies most forces and names most correctly. Limited (1–2): Classifies or names some forces with errors. |
| Communication and scientific vocabulary | 15% | High (3): Explains ideas clearly using correct scientific vocabulary (force, balanced, unbalanced, contact, at a distance, friction, gravity, magnetism) throughout. Sound (2): Explains clearly with some scientific vocabulary. Limited (1): Ideas are unclear or use little scientific vocabulary. |