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Homework Help: Kinetic Energy -- when a moving lorry breaks to avoid a collision?

  1. Oct 30, 2014 #1
    Hi there, Ive been given a statement in which I need to find out where Kinetic Energy goes when a moving lorry breaks to avoid a collision?

    There are no equations given. Only information needed to complete the question.

    I have tried looking around the internet to see what the possible answer could be. I understand there is an equation to find out how much kinetic energy is used. I just don't know where the energy goes.
    Last edited by a moderator: Oct 30, 2014
  2. jcsd
  3. Oct 30, 2014 #2


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    Does the lorry break into two or more pieces or does it brake (as in come to a stop, presumably in one piece?)
  4. Oct 30, 2014 #3


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    How do brakes work?
    Rub your hands together. What do you notice?
  5. Oct 30, 2014 #4


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    Hello Charlie, and welcome to PF :)

    Nice interpretation of the template (template? Yes, template! The one you inadvertently lost, thus blocking helpers from helping you without breaking PF rules). The idea is that you collect the relevant equations needed and list them under 2). If any equations are given in the problem statement, you can place them under 1).

    Braking means reducing speed by exercising friction forces (no friction, no speed reduction: beng!). Brake hard enough and the wheels block, leaving skidmarks on the road. A lot of work is needed to make them big tyres screech broad marks on the asphalt.
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