Question

The helicopter in the drawing is moving horizontally to the right at a constant velocity. The weight of the helicopter is W=52400 N. The lift force L generated by the rotating blade makes an angle of 21.0° with respect to the vertical. (a) What is the magnitude of the lift force? (b) Determine the magnitude of the air resistance R that opposes the motion.

Answer 1

Explanation:

It is given that,

The weight of the helicopter, W = 52400 N

The lift force L generated by the rotating blade makes an angle of 21.0° with respect to the vertical. The attached figure shows the free body diagram of the helicopter.

(a) Let L is the magnitude of the lift force.

The net force acting in the vertical direction,

$L\ cos\theta-W=0$

$L=\dfrac{W}{cos\ \theta}$

$L=\dfrac{52400}{cos(21)}$

L = 56127.99 N

$L\ cos[tex]L=5.61\times 10^4\ N$

(b) The net force acting in the x direction is :

$L\ sin\theta-R=0$

$R=L\ sin\theta$

$R=5.61\times 10^4\times \ sin(21)$

$R=2.01\times 10^4\ N$

Hence, this is the required solution.