Physics

Problem

A particle moves in x-y plane under the influence of a force

\vec{F}

such that its linear momentum is

\vec{P}(t) = \hat{i} \cos(kt) - \hat{j} \sin(kt)

. If

k

is constant, the angle between

\vec{F}

and

\vec{P}

will be: (a)

\frac{\pi}{2}

(b)

\frac{\pi}{6}

(c)

\frac{\pi}{4}

(d)

\frac{\pi}{3}