- Oct 12, 2013
- Uni Grad
Q20) B <--- darn this i put 154 into equationQ20 should be A. Its a tricky question. You need to calculate 'y' which is 96, as the top half of the beam undergoes compressive stress. 'm' can be calculated by drawing up a basic SFD and BMD, which is 12kNm. Plug it into the bending stress formula, and it would be approximately 11.3MPa. The given area is useless information. Q10 answer:B would make some sense, as you'd average out the radii to get 16.5, which is the radius along the neutral axis. IDK about 14, I put down B for that.
the F in part i is overcoming the weight.The power question would be different. You will need to calculate the new force as instead, you are pulling the boat up the plane which would constitute to a mix of frictional and weight pulling down the plane you'd need to overcome. This means you cannot use the answer from part (i) for this question. I think its approximately 4kW.
i did the calculations and ended up with zero, therefore to double check i looked at the joint F (i believe that it was this joint on the top of my head) and it had three members there. I could not close the force polygon if i tried to include all three members, but i could by omitting DF, therefore im quite certain its redundant. (if you wanted my thought process =D)omg i spent so long in the exam wondering why equilibrium was being violated :'(