The angle between the two force of magnitude 20N and 15N is 60 degrees (20N force being horizontal) determine the resultant in magnitude and direction

Respuesta :

Answer:

The magnitude of the resultant is 30.4 N.

The resultant angle direction is 25.3°.

Explanation:

To find the resultant of the magnitude and direction for given forces “P” and “Q” are 20 N and 15 N respectively, the angle (θ) between them is 60°.

We know that from triangle law of forces,  

[tex]R=\sqrt{P^{2}+2 P Q \cos \theta+Q^{2}}[/tex]

Substitute the given values in the above formula,

[tex]R=\sqrt{20^{2}+2 (20)(15) Q \cos 60+15^{2}}[/tex]

[tex]R=\sqrt{400+600(0.5) + 225}[/tex]

[tex]R=\sqrt{400+300 + 225}[/tex]

[tex]R=\sqrt{925}[/tex]

R = 30.4 N

The magnitude of the resultant is 30.4 N.

To find the direction of the resultant we know that [tex]\text {Resultant angle}=\tan ^{-1} \frac{Q \sin \theta}{P+Q \cos \theta}[/tex]

Substitute the given values in the above formula,

[tex]\text {Resultant angle}=\tan ^{-1} \frac{15 \sin 60}{20+15 \cos 60}[/tex]

[tex]\text {Resultant angle}=\tan ^{-1} \frac{12.99}{20+7.5}[/tex]

[tex]\text {Resultant angle}=\tan ^{-1} \frac{12.99}{27.5}[/tex]

[tex]\text { Resultant angle }=\tan ^{-1} 0.472[/tex]

Resultant angle=25.3°

The resultant angle direction is 25.3°.

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