Question 1: Define work done in the context of physics.

Answer: Work done is the transfer of energy when a force is applied to an object and causes displacement in the direction of the force.

Question 2: State the condition that must be met for work to be considered done on an object.

Answer: A force must cause displacement of the object in the direction of the force.

Question 3: What is the SI unit of work done?

Answer: Joule (J)

Question 4: Explain how work done relates to energy transfer.

Answer: Work done is a measure of energy transfer from one form to another when a force causes displacement. When work is done on an object, energy is transferred to or from that object, often resulting in a change in its kinetic or potential energy.

Question 5: Calculate the work done when a force of 50 N moves an object 10 meters in the direction of the force. Show your formula and answer with units.

Answer: Work done = force × displacement = 50 N × 10 m = 500 Joules (J)

Question 6: A worker pushes a box with a force of 200 N across a floor for 5 meters. How much work is done? Show your calculation.

Answer: Work done = 200 N × 5 m = 1000 Joules (J)

Question 7: Multiple Choice: Which of the following conditions results in no work being done?

Answer: D

Question 8: Fill in the blank: Work done is zero when the applied force does not cause any __________.

Answer: displacement

Question 9: Describe a simple experiment to demonstrate that work is done when lifting an object.

Answer: One can lift a small object, such as a book, vertically and measure the effort required. When lifting, work is done against gravity, which can be calculated as weight (mass × gravity) multiplied by height lifted. The experiment shows that energy is transferred to the object, increasing its gravitational potential energy.

Question 10: Identify the key variables that affect the amount of work done when pushing an object across a surface.

Answer: The magnitude of the force applied, the distance moved, and the direction of the force relative to displacement.

Question 11: In real-world applications, how does understanding work done help in designing energy-efficient machines?

Answer: Understanding work done allows engineers to minimise unnecessary energy loss by reducing friction and other resistive forces, thus designing machines that transfer energy more efficiently and save fuel or electrical energy.