Answer:
Explanation:
Given
Weight of helicopter [tex]W=53800 N[/tex]
inclination of blades with vertical [tex]\theta =21^{\circ}[/tex]
Suppose [tex]F_l[/tex] is the lifting Force
Now using F-B-D
[tex]F_{net}=0[/tex] as helicopter is moving with constant velocity
balancing forces in Vertical Force
[tex]F_l\cos \theta -W=0[/tex]
[tex]F_l\cos \theta =W[/tex]
[tex]F_l=\frac{W}{\cos \theta }[/tex]
[tex]F_l=\frac{53800}{\cos 21}[/tex]
[tex]F_l=57,627.6\ N[/tex]
Now sin component of lift is air resistance
[tex]F_l\sin \theta -R=0[/tex]
where R=air resistance
[tex]R=F_l\sin \theta [/tex]
[tex]R=57,627.6\times \sin (21)[/tex]
[tex]R=20,651.88\ N[/tex]