Level 1: Core Concepts Check (Aiming for a Pass - 'S')

1. Define: What does it mean for an object to be in equilibrium?

2. List: State the two conditions required for complete equilibrium.

3. Identify: If two forces keep an object in equilibrium, what must be true about their magnitudes and directions?

4. Define: What is the Center of Gravity?

5. Recall: Where is the center of gravity of a uniform ruler?

6. Define: What are coplanar forces?

7. True or False: An object moving at a constant speed in a straight line is in equilibrium.

8. Recall: A lamp of weight 20 N hangs from a cable. What is the tension in the cable?

9. Identify: For three parallel forces to be in equilibrium, what must be true about their directions?

Level 2: Connecting the Dots (Aiming for a Credit - 'C')

1. Explain: A car is parked on a hill. Draw a simple diagram showing the three non-parallel forces (weight, friction, normal reaction) that keep it in equilibrium.

2. Describe: A light plank is supported by two pillars, one at each end. If a person stands in the middle of the plank, how is their weight shared between the two pillars?

3. Explain: Why is a tall, narrow bus more likely to tip over on a sharp corner than a low, wide racing car? (Use the concept of center of gravity and base of support).

4. Apply: If three non-parallel forces are holding an object in equilibrium, what is the special condition about where their lines of action must meet?

5. Discuss: An object has zero resultant force acting on it. Does this guarantee it is in complete equilibrium? Explain your answer. (Hint: think about rotation).

Level 3: Exam Challenge (Aiming for a Distinction - 'A'/'B')

1. Analysis: A uniform beam of weight 100 N and length 4 m is supported by two pivots, A and B, at its ends. A box of weight 300 N is placed on the beam, 1 m from pivot A. (a) Draw a labeled diagram showing the beam and all four forces acting on it. Mark the position of the beam's center of gravity. (b) For the beam to be in equilibrium, what must be the sum of the upward forces from pivots A and B? (c) By taking moments about pivot A, calculate the upward support force from pivot B. (