Work And Power
Overview
Every machine, engine and living body does work by applying forces over distances. The amount of work you do equals the energy you transfer, and how quickly you do it determines your power.
In this lesson you will learn the equations for work done, gravitational potential energy and kinetic energy, see how conservation of energy links them, and calculate power as the rate of doing work.
Objectives
- Know and use the relationship: work done = force x distance moved
- Know that work done is equal to energy transferred
- Know and use the relationship for gravitational potential energy
- Know and use the relationship for kinetic energy
- Understand how conservation of energy produces a link between gravitational potential energy, kinetic energy and work
- Describe power as the rate of transfer of energy or the rate of doing work
- Use the relationship between power, work done and time taken
Mind map
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Flashcards
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Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Work And Power. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- Work done is calculated using: A) W = mv B) W = Fd C) W = mgh D) W = Pt Answer: B
- 1 watt is equal to: A) 1 J/min B) 1 N/s C) 1 J/s D) 1 kg m/s Answer: C
- Doubling the speed of an object multiplies its KE by: A) 2 B) 4 C) 8 D) 0.5 Answer: B
- A 2 kg ball at 10 m height has GPE (g = 10 N/kg) of: A) 20 J B) 200 J C) 100 J D) 2000 J Answer: B
- Power is defined as: A) Force x distance B) Energy x time C) Rate of doing work D) Mass x acceleration Answer: C
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