THIS THREAD HAS BEEN MOVED FROM ANOTHER FORUM BECAUSE IT IS HOMEWORK. BUT THERE IS NO TEMPLATE. Hi everyone, The problem gives that a particle moves in a circle with angular velocity ω. I know that r×ω=v, which is the velocity of the particle. However, I am told to differentiate and find τ=Iα but, using the product rule, I found a=(v×ω)+(r×α). I am not sure where to go from here as these quantities don't seem familiar to me. Was there a step I missed or is there something I am missing in this step? Thanks so much for any help.