• Question: You said that energy can't be created or destroyed, it just is. So you spoke of converting it and I wondered. Would yo lose energy in the process? If so, what converstion loses the most energy, and if not, what is the most efficient way of converting energy?

    Asked by to Saiful, Petra, Jenny, Jawwad, Iain, Bethan on 17 Jan 2017. This question was also asked by .
    • Photo: Jawwad Darr

      Jawwad Darr answered on 17 Jan 2017:


      most processes will end up being less than 100% efficient in terms of transforming from one type of energy to another. The energy that is “lost” isgiven out or dissipated as heat depending on the circumstances ( so is not really lost is just not doing useful something useful).

      For example in many types of car engines a lot of heat is generated and this heat is not being used to power the vehicle. so better way to think of it really is that all processes are not hundred percent efficient when it comes to energy transfer from one type to another, and the cases where energy transfer is generally generating a lot of unwanted heat (that is not be useful some purpose) are effectively wasting energy

    • Photo: Saiful Islam

      Saiful Islam answered on 19 Jan 2017:


      Yes, I mentioned that energy can neither be created nor destroyed; rather, it transforms from one form to another. This relates to what is called the law of conservation of energy – the total energy of a system remains constant over time. I used a simple candle in lecture 1 which converts chemical energy (of the wax) to light and heat. But overall, no energy is lost – just converted from one form to another. (There are processes that don’t do the full energy conversion you want and have ‘wasted energy’, which Jawwad Darr nicely describes.)

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