⚡ Part 1: Multiple Choice

Circle the best answer for each question.

1. Which of the following is an example of a non-contact force?

Friction between a shoe and the ground

Gravity pulling a ball downward

A hand pushing a shopping trolley

Air resistance on a moving car

2. A force is measured in which unit?

Kilograms (kg)

Joules (J)

Newtons (N)

Watts (W)

3. Two forces act on a box: 15 N to the right and 10 N to the left. What is the net force and direction?

25 N to the right

5 N to the left

5 N to the right

0 N — balanced

4. Which simple machine works by using a wheel with teeth that meshes with another to transfer motion?

Pulley

Lever

Gear

Wedge

5. Select ALL forces that are examples of contact forces:

Friction

Magnetism

Buoyancy

Electrostatic force

Air resistance

✏️ Part 2: Short Answer

Answer each question in full sentences where required.

6. A force can cause three types of changes to an object. Name all three and give one example of each.

7. Explain the difference between balanced and unbalanced forces. What happens to an object's motion in each case?

8. Describe how friction can be both useful and a disadvantage. Give one example of each.

9. Fill in the blanks using the words in the box below.

Word bank: inclined plane, screw, wedge, lever, pulley, wheel and axle

a) A ramp used to push a heavy box onto a truck is an ___________________________.

b) A door handle connected to a rod is an example of a ___________________________.

c) A bolt that holds two pieces of metal together is a ___________________________.

d) A flagpole uses a ___________________________ to raise a flag with less effort.

e) An axe splitting wood uses a ___________________________ to direct force outward.

🔢 Part 3: Problem Solving

Show all working and include units in your answers.

10. A student uses a spring scale to measure the weight of their science textbook and gets a reading of 12 N. Two students then push the same book across a desk — one pushes with 20 N to the right, and the other pushes with 8 N to the left.

a) What is the net force acting on the book? In which direction will it move?

b) If the students want the book to remain stationary (balanced forces), what force must the second student apply?

11. A construction worker needs to lift a 600 N load onto a platform 3 metres high. They choose to use an inclined plane (ramp) that is 9 metres long instead of lifting it straight up.

a) Using the formula Mechanical Advantage = Length of ramp ÷ Height, calculate the mechanical advantage of the ramp.

b) How does using the ramp make the worker's job easier? Explain using the concept of force.

12. In the space below, draw a labelled diagram of a first-class lever. Label the fulcrum, effort force, load, and show the direction of each force with arrows.