1. Oct 15, 2015

### werson tan

1. The problem statement, all variables and given/known data
for M2 , if i take the moment at pont C , then my ans would be (0.3i) x ((125X(3/5) j +125(4/5) k )= 30j +22.5k
Which is not same with the book which use moment about D . why ? Is the value at the triangle at te upper part incorrect (circle part) ?

2. Relevant equations

3. The attempt at a solution

#### Attached Files:

• ###### 6.png
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2. Oct 15, 2015

### paisiello2

Picture is too small to read.

3. Oct 15, 2015

### werson tan

#### Attached Files:

• ###### 6.png
File size:
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Views:
47
4. Oct 15, 2015

### paisiello2

Still too small. Just blow up the diagram.

5. Oct 16, 2015

### haruspex

If you are taking moments about C then presumably you are considering the force at D. Isn't that in the direction -3/5j+4/5k? And should't the displacement vector be -3i?

6. Oct 16, 2015

### werson tan

Ya, I would ended up getting 22.5k +30j . But if I take moment about D , I would get 22.5j+30k... Is it correct???

7. Oct 16, 2015

### haruspex

No, sorry, I had it wrong. The force at D is in the direction -4/5j+3/5k.