1. The problem statement, all variables and given/known data So I am studying for my finals at the moment, and I came across a problem that I am not really sure how to assess. I am given that the velocity of a particle is determined by vx=12t2-5t, vy=15t3-6t. It wants me to find when the acceleration of the particle will be zero at time t. Because the equation is in parametric form, I am kind of confused by it, and am unsure of what I am supposed to use to determine the acceleration at a given time. The answer will also be never, but I am unsure how that is determined. 2. Relevant equations I thought maybe because acceleration is determined from the derivative of velocity, use (dy/dt)/(dx/dt) but after researching a little bit, I found the equation: ||a||=√((d2x/dt2)2+(d2y/dt2)2) 3. The attempt at a solution So using the second equation: ||a||=√(242+(90t)2) 0=√(576+8100t2) 0=576+8100t2 -576/8100=t2 √(-576/8100)=t So this would seem like it is the correct way to assess the problem, considering t doesn't exist for a=0. Did I do this right? Or is there another way to do it? If so, what is the correct equation(s) to use?