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

1. Define: What is a resultant force?

2. Calculate: If you push a box with 10 N and your friend pushes in the same direction with 15 N, what is the resultant force?

3. Calculate: A forward thrust of 20 N acts on an object, and a backward friction of 5 N acts on it. What is the resultant force?

4. Identify: What is the resultant force on an object that is stationary?

5. Identify: What is the resultant force on an object moving at a constant velocity?

6. Define: What are "balanced forces"?

7. Define: What are "unbalanced forces"?

8. Recall: If forces are unbalanced, what happens to the object's motion?

9. Recall: What are collinear forces?

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

1. Explain: A tug-of-war is taking place. Team A pulls with 500 N and Team B pulls with 500 N. Describe the motion of the rope and explain why, in terms of the resultant force.

2. Apply: Two parallel forces of 20 N and 30 N act downwards on a light rod. What is the total upward force required to keep the rod in equilibrium?

3. Describe: A car's engine provides a forward force of 1000 N. The total resistive forces (friction and air resistance) are 800 N. Calculate the resultant force and describe what will happen to the car's speed.

4. Explain: If you want to achieve the largest possible resultant force when pushing a heavy object with a group of people, how should everyone apply their force?

5. Connect: How does the concept of resultant force relate to Newton's Second Law (F=ma)?

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

1. Problem-Solving: A parachutist of weight 800 N opens her parachute. The parachute provides an upward drag force of 1000 N. (a) Draw a simple diagram showing the forces acting on the parachutist. (b) Calculate the magnitude and state the direction of the resultant force. (c) Based on your answer in (b), describe what is happening to the parachutist's speed at this moment. (d) A short while later, the parachutist is falling at a constant velocity. What is the magnitude of the upward drag force now?