1. The problem statement, all variables and given/known data A particle moves along the positivex-axis .At time t seconds after leaving a fixed point O from rest, the displacement of the particle from O is x cm. The acceleration, a of the particle is defined by a=5-3t , 0<=t<=1 =-(4t+1), t>1 Find the speed of the particle when x=2.5 2. Relevant equations 3. The attempt at a solution Integrate twice to get the displacement function, x=5t^2/2-t^3/2 , 0<=t<=1 = -2/3t^3-2t^2 ,t>1 so 5t^2/2-t^3/2=2.5 solving this does not give me the answer. Where have i gone wrong?