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you need

- - handle;
- - pencil;
- - line;
- - protractor;
- - Calculator;
- - paper records.

Guide

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1

**in theoretical mechanics**

**forces have treated as a sliding vector.That is, the vector****forces can be transferred along the lines on which they are located.Consequently, the directions of the two forces****, applied to the body, intersect at point A. If the condition of the problem you need to find****resultant**two**forces, acting on the body along a straight line, the scalar values â€‹â€‹countervailing forces****deducted.A**

**forces**, attached in the same direction, added.

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2

Another case - when two
al method.

**s forces act on the body at an angle to each other.To add****forces**s in this example, you need to know the angle between their vectors.Find**resultant forces can**graphical and graph-analytic

3

graphical method vectors are added by the rule of parallelogram, or triangle.For example, given two

**forces**s 5,5N and 11,5N, the angle between them is equal to 65o.To find**resultant****forces**, first select the scale of the plotting.For example, 1cm = 1N.Iz point A at an angle of 65o to each other aside vector a, equal to 5.5 cm, and b, equal to 11.5 cm. In the parallelogram draw the vector sum of the two forces**.Its length in this scale equals scalar resultant forces****s - 14,5N.To add****forces**s graphical method by the triangle rule, position the start of the second vector in the end of the first.Construct a triangle.The length of the sides in this scale - it is a scalar value of the sum of forces**.**

4

When two forces

**graph-analytic method, you can not respect the scale of the construction of the drawing.Construct a triangle or a parallelogram similar to step 3. cosine get the side of a triangle or the diagonal of the parallelogram AC: c = (b ^ 2 + a ^ 2-2bc cosb) ^ 1/2;where a, b - two scalars vectors attached****forces**, b - the angle between them in a triangle.As seen from the drawing, an angle b = 180-a.** **