posted by Cynthia .
A fire helicopter carries a 520-kg bucket of water at the end of a 20.0-m long cable. Flying back from a fire at a constant speed of 40.0 m/s, the cable makes an angle of 38.0° with respect to the vertical. Determine the force exerted by air resistance on the bucket.
Draw a free body diagram. Note that three forces act on the bucket: weight, air resistance and rope tension. Because the velocity is constant, the three forces must balance.
A bit of trigonometry will tell you what the air resistance is.
I do not want to deprive you of the learning experience of doing it yourself.