Air resistance on a suspended object in motion

AI Thread Summary
To calculate the force of air resistance on a suspended water bucket from a helicopter, it is essential to recognize that the helicopter's constant speed indicates zero acceleration, leading to a net force of zero. The forces acting on the bucket can be divided into vertical and horizontal components, with tension in the cable opposing the weight of the bucket and air resistance. The vertical component of tension can be expressed as Tcos(θ), while the horizontal component is Tsin(θ), where θ is the angle with respect to the vertical. By establishing equilibrium, the horizontal air resistance can be equated to the horizontal component of tension. This approach allows for the calculation of air resistance without directly involving tension, leading to a clearer understanding of the forces at play.
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Homework Statement


A fire helicopter carries a 625 kg empty water bucket at the end of a cable 21.7 m long. As the aircraft flies back from a fire at a constant speed of 36.6 m/s, the cable makes an angle of 35.3° with respect to the vertical. Calculate the force of air resistance on the bucket.

Homework Equations


F=ma.
Fnet=0


The Attempt at a Solution


I started with the rationalization that constant speed implies 0 acceleration, meaning Fnet=0 in both the x and y direction.
Dividing the forces up into Fnety=T(tension in the cable)-W(mg)
and Fnetx is where I get stuck. If the acceleration is 0, then which force is opposing air resistance?
Should I be calculating the horizontal component of the displacement from the vertical?
Help, please!
 
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You don't need to get into wire tension. The weight (W) acts straight down, and the horiz air resistance force (Fx) acts left. These horiz and vert forces are trig related , using the given angle. The resultant of these 2 forces, W and Fx, must lie in the direction of the cable, from equilibrium consideration.
 
If you want to use tension you can and then just cancel it out by dividing the x forces equation by the y forces equation.

You'll have the upward Ty = F wt and the horizontal Tx = F air resistance
The y component of T is of course Tcos of your vertical angle and the x component, Tsin of the vertical angle.

When you divide T's cancel and you have the same equation as the one you'll get if you use PJ's faster method.
 
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