Science ks3

[mrsglowglow]

My Son has done a simple graph but stuck on the calculation. Any help appreciated.

Is the graph a straight line? If so you continue the line onwards and then find where it crosses the 1200 mark and what the strength would be at that point.

No it isn't a straight line but more of a curve. He missed the lesson so will have to ask the teacher.

Just check he's plotted the axes correctly (aggregate on x, strength on y) and done a reasonable curve of best fit and continue the curve past 1200 on x axis. No calculation involved, the 'working' would just be using a ruler to pencil from 1200 to the curve then same to the y axis to give the answer.

Thanks for your help. He was over complicating

I don't imagine any engineer would be happy at determining the strength of some concrete by extrapolating beyond the known data! Extrapolating is a big no-no in most science (not to say it doesn't happen, and obviously no choice in order to answer this question).

If he does become an engineer though, the training will probably include not to calculate concrete strength for a bridge by extrapolating a wee graph. (I hope...)