Guide

1

To determine

**resultant**, you need to find the total force**, the effect of which is equivalent to the combined effect of all forces.To do this, apply the laws of vector algebra, as any physical force has a direction and a module.There is a principle of superposition in which each body acceleration force reports, regardless of the presence of other forces.** 2

Draw a graph of the problem, using a vector to represent forces.The beginning of each such vector - this is the point of force application, i.e.the body itself or body, if considered mechanical system.For example, the gravity vector to be directed vertically downward direction of the vector of the external force coincides with the direction of movement, etc.

3

Look carefully at the chart.Determine how various vector forces facing each other.De
pending on this, make a calculation of their resultant.In accordance with the principle of superposition it is equal to the geometric vector sum of all forces.

4

four situations may occur: Forces in the same direction.Then the vector is collinear with the resultant of these forces and their sum is equal to: | F | = | f1 | + | f2 | .Sily pointing in different directions.In this case, the module of the resultant difference is greater and lesser modules strength.Its vector is directed in the direction of greater strength: | F | = | f1 | - | f2 |, where | f1 | & gt;| f2 | .Sily directed at a right angle.Then calculate the unit of the resultant vector addition triangle rule.Its vector is directed along the hypotenuse of a right triangle formed by the vectors forces.The beginning of the second vector coincides with the end of the first, therefore, the direction of the resultant will again be determined by the direction of greater strength: | F | = √ (| f1 | ² + | f2 | ²) .Sily directed at an angle other than 90 °.In the parallelogram of vector addition unit resultant is: | F | = √ (| f1 | ² + | f2 | ² - 2 • | f1 | • | f2 | • cos α), where α - the angle between the forces f1 and f2,the direction is determined by the resultant of the previous case.