Question

Two forces each of 20n acting on body at 120°.The magnitude and resultant is ??

Answer 1

LET the two equal forces be 20 N each

acting at 120 degree

We know resultant of two forces is given by

$R = \sqrt{20^{2} + 20^{2} + 2*20*20* cos120 }\\ \\ R = \sqrt{2*400 + 2*400*(-0.5)} \\ \\ R = \sqrt{2*400-400} \\ \\ R = \sqrt{400} = 20 N$

Magnitude is 20 and resultant force is 20 N

Answer 2

LET the two equal forces be 20 N each

acting at 120 degree

We know resultant of two forces is given by

\begin{gathered} R = \sqrt{20^{2} + 20^{2} + 2*20*20* cos120 }\\ < br / > < br / > \\ R = \sqrt{2*400 + 2*400*(-0.5)} \\ \\ R = \sqrt{2*400-400} \\ \\ R = \sqrt{400} = 20 N\\ \\ \end{gathered}

R=

20

2

+20

2

+2∗20∗20∗cos120

<br/><br/>

R=

2∗400+2∗400∗(−0.5)

R=

2∗400−400

R=

400

=20N