# How to find the positon of a local vector

1. Oct 27, 2015

### Aceix

1. The problem statement, all variables and given/known data
Determine the resultant force R that is equvalent to the forces exerted by the tugboats on the barge. Specify the coordinates of the point on the x axis through which R passes.
Pls check attached file!

2. Relevant equations
Moment=Force x perpendicular distance

3. The attempt at a solution
Findin the R resulted to 15.7i + 11j
Total moment about A gives 8tons.m clockwise.
Then using this force-couple system, the resultant force should be placed such that it yields the same moment.
Letting x be the distance between Ry(y component so I get a perpendicular relationship) and pt. A, and equating the moment(that of R and the 8tons.m) reveals that x=0.7m. Then the coord is 60m-.7m=59.3m.

#### Attached Files:

• ###### IMG_20151028_025533.jpg
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2. Oct 28, 2015

### haruspex

You forgot something.

3. Oct 28, 2015

### Aceix

Dont see anything. What did I miss?

4. Oct 28, 2015

### haruspex

The force is 8 tons. What is the moment from the force about A?

5. Oct 31, 2015

### Aceix

Oh..60x8tons.m

6. Oct 31, 2015

### Aceix

So...55.6m?

7. Oct 31, 2015

### haruspex

As x coordinate? Seems much too large. Please post your revised working.