Here is our OPTIONAL homework assignment…a few light problems from Chapters 8 and 9. If you are handing these in, they are due on Wed. 12/5 at 4 pm.
Chapter 8: 8-6, 8-19 (a final exam problem in previous years), 8-35, 8-37, 8-40
Chapter 9: 9-57 (already done, several times!), 9-59, 9-61, 9-129
Use this post as an open thread for discussion.
9 responses so far ↓
1 John // Dec 4, 2007 at 7:31 pm
Anyone have any clues for 8-19? and the the last part of 9-61?
2 hambut // Dec 4, 2007 at 8:44 pm
i know you want to make a few FBDs, one of one of the tongs, and only one since they are symmetrical, one of the crate and pallet, and one of the block that the tongs are holding. im only getting stuck cause of the forces on joint C, they shouldnt matter, but i cant figure out how to get around them. hope that helps in a way. howd anyone do the FBD for 8-37?
3 hambut // Dec 4, 2007 at 9:29 pm
for 9-61, i split it in two triangles and two rectangles, and i knew that the y tilda for a triangle would equal (2/3)h. and then i just followed the table like normal
4 kls2ycc // Dec 5, 2007 at 12:36 am
did anyone get 9-129? I dont know how to take into account that the vertical concrete beam gets bigger as it goes down and the specific gravity to find the weight?
5 hambut // Dec 5, 2007 at 12:55 am
split the vertical concrete part into a rectangle (12 x 1) and a triangle (12 x 0.5). then you can find the centroids of each. im not sure how to find the weight. anyone have ideas about 8-37 and 8-40?
6 Vfort // Dec 5, 2007 at 1:02 am
For 8-37 I first made an FBD of the top crate to find the min. force required for the crate to slip. Then I made one of the two boxes together to determine whether the box would tip or slip and the min. force required. Then I made one more FBD of the man to determine the max. push he could withstand before sliding. For 9-129 I split the concrete wall into two rectangles and a triangle. To find the weight you multiply the specific gravity by the volume of the wall (just look at the units). Does anyone understand how to do 9-40?
7 Vfort // Dec 5, 2007 at 1:04 am
I mean 8-40
8 hambut // Dec 5, 2007 at 1:10 am
thanks, ill try that….uhhh we didnt have to do 9-40
9 hambut // Dec 5, 2007 at 1:11 am
wait nevermind sorry
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