Question

A force 5N and 20N are acting at an angle of 60°find the resultant force in magnitude and direction

Answer 1

work done is equal to force multiply displacement
Work done equal to 5N multiply displacement cos 60
Solve

Answer 2

$resultant \: force \: \\ = \sqrt{ {20}^{2} + {5}^{2} + 2 \times 5 \times 20 \cos(60) } \\ = \sqrt{400 + 25 + 100} \\ = \sqrt{525} = 5 \sqrt{21} \\ resultant \: direction \\ = \frac{q \sin( \alpha ) }{p + q \cos( \alpha ) } \\ = \frac{20 \sin(60) }{5 + 20 \cos(60) } \\ = \frac{10 \sqrt{3} }{15} = \frac{2}{ \sqrt{3} }$