Work and Energy

• What is the definition of work done?

  Measure of energy transfer
• What does the equation W = Fd represent?

  Work done equals force times distance
• What does the law of conservation of energy state?

  Total energy remains constant during transfer
• What is gravitational potential energy (GPE)?

  A bodys energy by virtue of its position
• What is the formula for potential energy?

  PE = mgh
• How does kinetic energy change with velocity?

  Kinetic energy increases with higher velocity
• What is the formula for kinetic energy?

  KE = ½(mv²)
• What is elastic potential energy?

  Energy stored when an object is deformed
• What is Hooke's Law?

  F = kx
• What does the spring constant (k) measure?

  Stiffness of the spring
• How is work done on a spring calculated?

  W = ½(Fx)
• What is the typical conversion rate of petrol engines?

  Less than 38%
• What causes energy loss in vehicles?

  Friction and drag forces
• How can vehicle efficiency be improved?

  By enhancing engine efficiency and reducing friction
• What is rolling resistance?

  Force needed to move the tyre forward
• What happens when a vehicle idles?


  It wastes energy and fuel
• What are the factors affecting energy efficiency in vehicles?

  • Engine size and power
  • Frictional forces
  • Drag forces
• What are the methods to reduce energy loss in vehicles?

  • Improve engine efficiency
  • Reduce frictional forces
• What are the consequences of exceeding a spring's elastic limit?

  • Plastic deformation occurs
  • Spring no longer obeys Hooke's Law
  • Permanent change in shape