Wednesday

October 1, 2014

October 1, 2014

Posted by **Iamxe** on Sunday, May 11, 2008 at 12:28pm.

I know I can find this using the law of cosines, but I think my teacher wants me to use some vector thing, but I do not know how to relate the two vectors to the equilibrant. Is it like u-v?

- precalculus -
**bobpursley**, Sunday, May 11, 2008 at 2:03pmHmmm. use the 427 Lbs at 0 degrees, then the cos18'20" * 369 is the force in the direction of zero degrees, and 369*sin18'20"is the force 90 degrees to that. Now add these two to see the resulatant, and then add180 degrees to get the equilibrant.

- precalculus -
**Damon**, Sunday, May 11, 2008 at 2:15pmWell, either way it is a "vector thing.

The "equilibrant" is equal and opposite to the "resultant" or sum of the two vectors. In other words it is the vector needed to cancel them.

I will find the resultant, then we can do minus signs.

I am going to say we have 369 pounds along the x axis and 427 pounds at 18 1/3 degrees above the x axis.

In vector notation that is

Rx = 369 + 427 cos 18.33

Ry = 427 sin 18.33

or

Rx = 369 + 405 = 774

Ry = 134

Our equilibrant has components then

Ex = -774

Ey = -134

That is in the third quadrant at

tan A = 134/774 where A is below the -x axis

A = 9.82 degrees below -x axis

or

189.8 degrees counterclockwise from x axis where our original 369 lb force was

**Answer this Question**

**Related Questions**

trigonometry - Find the magnitude of the resultant force and the angle between ...

math - Forces are applied to two ropes which are attached to the bumper of a ...

Physics - A sign whose weight is 95 lbs is held up by a chain. (1) With what ...

Geometry - Two forces are pushing on an object, one at 12 lbs of Force and one ...

geometry - Two forces are pushing on an object, one at 12 lbs of Force and one ...

geometry - Two forces are pushing on an object, one at 12 lbs of Force and one ...

geometry - Two forces are pushing on an object, one at 12 lbs of Force and one ...

math - A fitness company surveyed the weights of its 90 costumers. Assume that ...

math - A fitness company surveyed the weights of its 90 costumers. Assume that ...

9th grade math - if a man mixes 12 lbs. of peanuts thats $1.25 a lbs. with a ...