1. The problem statement, all variables and given/known data An object moves with its position obeying x=5t^2-6t^2 and y=3t^-1+4t^4. What is the magnitude of its acceleration at t=1s; a)57 m/s^2 b)34 m/s^2 c)26 m/s^2 d)44 m/s^2 e)0 m/s^2 2. Relevant equations x=5t^3-6t^2 y=3t^-1+4t^4 3. The attempt at a solution Second derivative of the displacement x is; ax=30t-12 m/s^2 Second derivative of the displacement y is; ay=8t m/s^2 t=1 -> ax ax = 18 t=1 -> ay ay = 8 Resultant acceleration = sqrt(18^2+8^2) = 19.69 Which is wrong according to the answer I found online which was a) 57 m/s^2. Anyone show me where I've messed up or is the answer I found wrong?