Question

Does anyone hereknow how to solve question 2.18 (the last question) from http://ocw.mit.edu/courses/civil-and-environmental-engineering/1-050-solid-mechanics-fall-2004/readings/emech2_04.pdf

Answer 1

Maybe, the mass of bus is 12,000 kg (length 15 m) average body mass = 70 kg, so a 45 seat bus gives loading of (70x46[driver also included]= 3,220 kg. Total is 15,500 kg say. How long is the bridge? Say a kilometer (1,000 m). There would be 134 buses. So the total mass on the bridge would be 15,500 x 134 = 2,077,000 kg. So the loading would be 2,077 kg per metre, or 20,770N per metre.

Answer 2

thank you for your help.. but here's a problem.. I was working on number 2.18 questio not 2.17.. i posted it wrong...
I always start questions like them by drawing a free body diagram, but since this is all twisted and so on I have no clue about how the free body diagram should look like.
Is it possible for you to check out that question and give me a hand on it?
Thank you so much