posted by John .
A duck has a mass of 2.70 kg. As the duck paddles, a force of 0.130 N acts on it in a direction due east. In addition, the current of the water exerts a force of 0.210 N in a direction of 52.0 ° south of east. When these forces begin to act, the velocity of the duck is 0.110 m/s in a direction due east. Find (a) the magnitude and (b) the direction (relative to due east) of the displacement that the duck undergoes in 2.70 s while the forces are acting. (Note that the angle will be negative in the south of east direction.)
Neglecting friction? I have never understood why competent teachers give problems such as this
I assume your teacher imagines there is no friction, but the current gives a force? What exactly is friction?
anyway, add the force vectors, get the resultant, then compute a=Force/mass, and assume any other friction in the water besides the current is magically not there.
Now knowing a, you can compute displacement
d=vi*t+1/2 a t^2