Methinks its a student question.
Putting my Sherlock holmes hat on:
1) Macauleys tends to be taught at schools but not generally practised in industry.
2) the OPs name has "88" which i take it they are only around 22 years old.
3)I must be getting grouchy
I have used double integration to solve stuff. Macauleys method is not completely accurate. Either I was not taught, or I did not remember this from school. It doesn't hurt to crack open the old textbooks once in a while.
88 could be a year of birth, it could be the numnber of Kierans on Eng-Tips. It could be the number of keys on a piano. It could be the size of a gun. It could be an Oldsmobile. It could be part of a famous rock and roll song.
It sounds like he has phyically tested this beam. At worst, we are not doing his homework, and it is not a dumb question.