Question

Given

u=rcos(wt)i+rsin(wt)j where r and w are constants, obtain the speed of the movement

Answer 1

$u=rcos(wt)i+rsin(wt)j\\ \text{speed,s=}\frac{du}{dt}\\ \text{speed,s=}-rwsin(wt)i+rwcos(wt)j$