Respuesta :
Answer:
a) The vertical component of the helicopters speed relative to the air = 0 m/s
The horizontal component of the helicopters speed relative to the air = -42.5 m/s
The vertical component of the wind speed relative to the ground = -21.65 m/s
The horizontal component of the wind speed relative to the ground = 12.5 m/s
b) The x-component of the helicopter speed relative to the wind speed = -30 m/s
The y-component of the helicopter speed relative to the wind speed = -12.5 m/s
c) The resultant speed of the helicopter relative to the ground is 32.5 m/s in the direction of W 22.6° S
Explanation:
The speed of the helicopter = 42.5 m/s
The direction of flight of the helicopter = West
The wind speed = 25.0 m/s
The direction of the wind = E30°S
a) The velocity components of the helicopters speed relative to the air are;
Vertical component = 0 m/s
Horizontal component = -42.5 m/s
The velocity components of the wind speed relative to the ground are;
Vertical component = -25 × cos(30) = -21.65 m/s
Horizontal component = 25 × sin(30) = 12.5 m/s
b) To find the speed of the helicopter relative to the wind we have;
x-component of the helicopter speed = -42.5 m/s
y-component of the helicopter speed = -0
x-component of the wind speed relative to the ground = 25×sin(30) = 12.5 m/s
y-component of the wind speed relative to the ground = -25×cos(30) = -21.65 m/s
Therefore, the x-component of the helicopter speed relative to the wind speed = -42.5 + 12.5= -30 m/s
the y-component of the helicopter speed relative to the wind speed = 0 + (-12.5) = -12.5 m/s
c) The resultant speed of the helicopter relative to the ground is given by the relation;
[tex]v_{h, ground} =\sqrt{(v_{h,horizontal})^2 + (v_{h,vertical})^2}[/tex]
= √((-30)² + (-12.5)²) =32.5 m/s
The direction of motion from the x-axis is given as follows;
[tex]tan(x) = \dfrac{Vertical \ velocity \ component}{Horizontal \ velocity \ component} = \dfrac{-12.5}{-30} = \dfrac{5}{12}[/tex]
[tex]x = tan^{-1} \left (\dfrac{5}{12} \right ) = 22.62 ^{\circ}[/tex]
Therefore, the helicopter is flying at 32.5 m/s in the direction of W 22.6° S.