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

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

Question 2: Explain why work is considered positive when an object is moved in the direction of the applied force.

Answer: Work is positive because energy is transferred to the object, increasing its energy.

Question 1: A worker pushes a box with a force of 50 N over a distance of 10 m in the direction of the force. Calculate the work done on the box.

Answer: Work done = 50 N × 10 m × cos(0°) = 500 Joules

Question 2: A car engine exerts a force of 2000 N to move a vehicle 100 m along a straight road. If the force acts at an angle of 30° to the direction of movement, what is the work done?

Answer: Work done = 2000 N × 100 m × cos(30°) ≈ 2000 × 100 × 0.866 = 173,200 Joules

Question 1: Describe a simple experiment to measure the work done when lifting an object vertically. Include the variables you would control and safety precautions.

Answer: An experiment can involve lifting different masses using a pulley and measuring the force applied and height lifted. Variables to control include the mass, lifting height, and lifting speed. Safety precautions include ensuring the lifting area is clear, using appropriate supports, and handling weights carefully to prevent injury.

Question 1: A person pushes a shopping trolley with a force of 30 N over a distance of 5 m along a level surface. The push is in the same direction as the trolley’s movement. Calculate the work done and describe what this indicates about energy transfer.

Answer: Work done = 30 N × 5 m × cos(0°) = 150 Joules. This indicates that 150 Joules of energy have been transferred from the person to the trolley, increasing its kinetic energy or overcoming friction.

Question 1: Explain how the concept of work done is important in the design of lifting equipment such as cranes.

Answer: Understanding work done helps in designing cranes that can safely lift heavy loads by calculating the energy transfer involved, ensuring the equipment can handle the required force and distance safely.

Question 2: Describe how energy transfer through work is utilised in everyday activities such as riding a bicycle.

Answer: When riding a bicycle, muscular effort does work on the pedals, transferring energy to the bicycle's motion, allowing it to move forward by overcoming resistive forces like friction and air resistance.