Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

Lv 56,897 points

jesusofnasareth

Favorite Answers32%
Answers1,173
  • Where does the energy come from?

    Imagine an iron cube with a weight of 1N on the floor. It has zero gravitational potential energy (GPE). If I lift it 1m up, it will have 1J of GPE, and I will have done at least 1J of work in order to lift the block. However if I use a fixed magnet fixed 1m above the ground (NOT an electromagnet) and the block is lifted up 1m the block gains 1J of energy, but the magnet has not done any work. Where does the energy come from as it can neither be created nor destroyed as we all know.

    2 AnswersPhysics1 decade ago
  • Where does the energy come from?

    Imagine an iron weight of 1N sat on a bench. It has zero energy. If it is then attracted to a fixed magnet, 1m above the bench, the weight would now have 1J of gravitational potential energy. Energy is nether created nor destroyed so where did this energy come from?

    2 AnswersPhysics1 decade ago