Difference between energy and force?

  1. What is difference between energy and force? Is energy just a measurement of a force?

    Thanks,

    S
     
  2. jcsd
  3. mathman

    mathman 6,619
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    Simple example: Holding a rope taut is using force. Pulling something with rope is using energy.
     
  4. enigma

    enigma 1,815
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    Energy is a 'property' which you have when a force is applied over a certain distance. It's sort of counting up all the force which has acted on you, and giving a number you can use to make calculations simpler.
     
  5. energy is sort of the potential to exert a force.

    more accurately, energy is the potential to do work, but work is a function of force.

    forces change the way things move. to make something move, change direction or stop moving, you need to exert a force on it. but you cannot exert a force unless you have the energy to do so.

    when you move your mouse, your hand exerts a force on the mouse to move it. the energy required to exert that force comes from the energy stored in your muscles.

    another example: think about bowling a ball at some skittles. when the ball is rolling, it has energy (kinetic energy), when it hits the skittles, it uses up that energy to exert a force on the skittles. the force knocks the skittles over. the movement of the ball gives it the energy to exert that force.
     
    Last edited: Oct 17, 2003
  6. krab

    krab 905
    Science Advisor

    A big difference between the two is that force can be changed to much larger or smaller values by simple devices such as levers, screws, etc. But energy is a conserved quantity. So a given quantity of energy can be expended by applying a relatively large force over short distance, or smaller force over longer distance.
     
  7. HallsofIvy

    HallsofIvy 40,769
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    Also important: there is a "conservation of energy" law. There is no "conservation of force". In order to lift an object with weight 1 Newton a height of 1 meter, I MUST do 1Newton* 1 meter= 1 Joule of work. But if I use an inclined plane instead of lifting it straight up, I can reduce the force necessary.
     
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