Physics please help
posted by Sushmitha on .
A duck has a mass of 2.8 kg. As the duck paddles, a force of 0.05 N acts on it in a direction due east.
In addition, the current of the water exerts a force of 0.15 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 2.2 s while the forces are acting
Draw a diagram of the forces. By the law of cosines, the resultant force is
f^2 = .05^2 + .15^2 - 2(.05)(.15)cos120°
f = 0.18N in the direction θ where
tanθ = -.15*√3/2 / .125
θ = -46° or, E46°S
Since F = ma, a = .125i - .13j
s = .5 at^2
= .5(.125i - .13j)*2.2^2
= 2.42(.125i - .13j)
= .3025i - .3146j
|s| = 0.436m