4.25. a)
Since there is no net acceleration, the sum of the forces in both the x and the y directions must be zero.
Solving for T in the equation for y and plugging that into the equation for x, we find that
b)
Now, the mass of the bucket has increased to 
. However,
the drag force 
is not dependent on the mass of the bucket,
only the surface area exposed to the air, which hasn't changed,
therefore we can rewrite our forces in the x and y directions, but
keep from part a.
To find the mass of the water, take and subtract the
weight of just the bucket.
Note that the values given for the length of the rope and for the velocity helicopter were eeded. Don't be confused by extra information.