Question

The resultant of two forces 2 KN and 6 kN which are acting at an angle 300 is

Answer 1

Units are not written in calculation.

Answer:

2√13 kN.

Explanation:

 300° can be written as 360° - 60°  ⇒  2π - 60°.

We know, period of cosine is 2π, so cos( 300° ) will be as same as cos( - 60° ) which is cos( 60° ), since cos( - 60° ) = cos( 60° ).

Resultant of those forces :

⇒ √[(2)^2 + (6)^2 + 2(2*6*cos60°)]

⇒ √[ 4 + 36 + 2(2*6*1/2)]

⇒ √[ 40 + 12 ]

⇒ √52

⇒ 2√13

        Hence,  resultant is 2√13 kN.