Question

A duck has a mass of 2.20 kg. As the duck paddles, a force of 0.120 N acts on it in a direction due east. In addition, the current of the water exerts a force of 0.240 N in a direction of 53.0° south of east. When these forces begin to act, the velocity of the duck is 0.120 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 2.60 s while the forces are acting. (Note that the angle will be negative in the south of east direction.)

Answer 1

a force of 0.120 N acts on the duck in a direction due east

water exerts a force of 0.240 N in a direction of 53.0° south of east.

The second force will have a component proportional to cos of angle in the east direction

and proportional to sine of the angle in south direction

The total force on the duck due east is

The total force due south is

The displacement in east direction is

The displacement in south direction is

a) The magnitude of displacement is

b) The direction relative to the east is

Angle is negative in the south of east direction