1. The problem statement, all variables and given/known data A particle moves in a plane described by the position vector r (t)= ( 2bsin( wt ))i + ( bcos( wt ) )j where b and w are some constants. The angle between its velocity and acceleration vectors at time t=(π/2w) a) is approximately 27 degree . b) is exactly 45 degree . c) is approximately 63 degree . d) is exactly 90 degree . e) cannot be determined since b and w are not specified. 2. Relevant equations differentiation 3. The attempt at a solution v(t) = (2bw(cos(wt)))i + (-bw(sin(wt))j a(t) = (-2bww(sin(wt)))i + (-bww(cos(wt)))j After that, how do i find the angles?