(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A duck has a mass of 3.0 kg. As the duck paddles, a force of 0.06 N acts on it in a direction due east. In addition, the current of the water exerts a force of 0.13 N in a direction of 60° south of east. When these forces begin to act, the velocity of the duck is 0.12 m/s in a direction due east. Find the magnitude and direction (relative to due east) of the displacement that the duck undergoes in 2.0 s while the forces are acting.

2. Relevant equations

ƩF = m*a

D = VoT + (1/2)aT^2

3. The attempt at a solution

Fx = 0.06 + cos(60)*.13 = .125 m/s

Fy = sin(60)*.13 = .113 m/s

sqrt(.125^2 + .113^2) = .1685N

.1685/3.0 = 0.0561 m/s^2

D = (0.12)(2) + (1/2)(.0561)(2)^2 = .3522

This is where I am confused, as I think I thought I was doing everything correct up until this point. When I enter this into the answer sheet it says it is wrong. I mistakenly used .13 for Fy instead of .113 and it gave me .326 m which is the correct answer.

Also I know to find the direction you use arctan(Fy/Fx) but I can't find it...

Any help is greatly appreciated.

Thank you.

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Newtons Law Problem involving kinematic equation

**Physics Forums | Science Articles, Homework Help, Discussion**