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 ????