Moments. Finding angle and force

SagarPatil · Jan 29, 2015

Homework Statement

Two Forces are acting concurrently and their resultant is 500 N as shown in figure on the right. Determine P and the angle P makes with the x-axis?

Vector addition diagram: force P at angle alpha to the X-axis plus a 200 N force, with a 5-12-13 right triangle marked, equals resultant R = 500 N on the right, shown with a 3-4-5 triangle.

2. The attempt at a solution

Handwritten solution on lined paper for a force problem: x-component 200 × 13/12 = 216.667, y-component 200 × 5/13 = 76.923, resultant P = √(76.923² + 216.667²) = 229.917, and tan⁻¹(76.923/216.667) = 19.55°, with a right-triangle sketch of the components.

Is my answer correct?[/B]

siddharth23 · Jan 29, 2015

I'm afraid it isn't. For one, you're x-component is larger in magnitude that the original force. And you haven't made use of the resultant of 500 N.
Use an equation such that the resultant of 'P' and the 200N vector is the 500N vector.

SagarPatil · Jan 31, 2015

siddharth23 said:

I'm afraid it isn't. For one, you're x-component is larger in magnitude that the original force. And you haven't made use of the resultant of 500 N.
Use an equation such that the resultant of 'P' and the 200N vector is the 500N vector.

I think this is what you mean.

Handwritten working on lined paper showing three triangle diagrams with side lengths 200, 300 and 500 and angles such as 53.13 and 126.87 degrees, plus the law of cosines for a side and a sine-rule line for angle B.

SagarPatil · Feb 2, 2015

I got the answer. :D

Moments. Finding angle and force

Homework Statement

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