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Glass Breaking

  1. Jun 8, 2006 #1
    First of all i would like to apologise if i have posted this query in the wrong part of the forum. I just could find any other headings which seemed appropriate for my some what un-physics related question.

    Basically at school i fell backwards onto a pain of glass and shatterd/broke it to the point where it was unrepairable and had to be replaced. The pain of glass cost £1500 to replace and the shcool are trying to force me to pay for a percentage of the glass.

    However the pain of glass is approximately 12ft by 7ft high, and i am told is reinforced, tested, 2inch thick glass. Basically, not being a glass expert, what i mean to say is that it is that super tough double glazed really strong glass. Being 15 years old and having a mass of about 55kg and a height of 5 ft 5 i fell backwards from a practically stationary position(i was tripped by my own stupity while talkin to a friend) into the glass hitting it just below the centre of the glass with my back/shoulder.

    Normally this robust glass takes a lot more force then a 15 year old boy falling with a 550N force into a glass with hardly any speed. Quite regularly a lot older boys are thrown or pushed into this glass pain during the course of an average school day as part of the normal hustle and bustle of a school day, ive seen people literally run into it without any damage to the glass, haha normally the damage is on the subject.
    Anyway, i would like to know if there is anyway i could physically prove that the glass was defect or flawed and my physical strain some mixed with this inital flaw in the class caused it to break.

    I know that this is an inaccurate query with very flawed points. But i am certain that the glass was defect. Even the teacher making me pay said that the glass takes a lot more abuse and it would be nearly impossible for me to break the glass in this way.

    If i found out the exact dimensions of the glass and the pressure/force need to break it perhaps this would help you in proving physically that the glass was initally flawed.

    Thank you for reading and any help would be greatly appriciated. I know my physics is obvious very elementry and flawed.

    I know this whole topic is most likley flawwed and nothing to do with physics but anythings worth a try, to get out of a £1500 bill. I just dont want to pay £1500 to a school that from past experience leads me to think is racist and genral twats(pardon the language)

    Thank you a lot for reading this and sorry if it is a waste of time.

    P=F/A ????
  2. jcsd
  3. Jun 8, 2006 #2


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    Nope, not going to show anything with physics with what you've told us. Best you could do would be to find out who made this amazing toughened 2 inch thick glass and ask them what kind of impact damage it should take. I'd agree that 2 inch thick glass in a school probably isn't supposed to break when a weedy kid gets pushed against it, but you'll not win any argument against your school if they have no respect for you.

    Besides, they can't actually make you pay for it anyway.
    Last edited: Jun 8, 2006
  4. Jun 8, 2006 #3


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    It's pretty obvious from your description of it that it was intended to be unbreakable by normal impacts. The school and/or the glass vendor was negligent in placing a defective pane where it could be broken in the manner that you said. The school has no right to charge you for it, but you could certainly charge them if you were injured in the incident.
  5. Jun 8, 2006 #4
    did you have something pointy on or around your shoulder?
    that would definately have done it..... you can break a car window with a pen, but kicking it wont do a thing

    happened to me with my friends car, i was throwing my backpack into his trunk, and a lock which i had attached to the top flew up and hit the glass with its tip and only the tip. it wasnt that hard. it was just the fact that it was pointy..

    just an idea

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