Using Graphical Method

Methode I: Using Graphical Method.

Procdures

Choose a scale for the axes

Draw the vectors at the given angle

Complete the Parallelogram of vectors.

Measure the length R of the diagonal

Multiply R by the scale to get the resultant Vector.

Method II: Using the Cosine Rule.

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Method III: By Resolving the Forces Horizontally and Vertically.

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Then;
FV = y = 3N
FH = x+8 = N

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Example 8

A mass of 15kg is suspended using a string. The string is then pulled by a horizontal force F such that the string makes an angle of 300 with the down ward vertical.

Calculate the;
(i) Tension in the string.
(ii) Horizontal force F.

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Example 9

A block of mass 2kg is pulled along a rough horizontal ground by a force of 120N, with the help of a string, which makes an angle of 600 with the horizontal. If the friction between the block and the ground is 50N,

calculate the;
(i) Resultant force on the block.
(ii) Acceleration of the block.

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Solution

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