Calculate y-component of the acceleration vector as the second derivative of "y" over t:= 4 m/s^2. Calculate x-component of the acceleration vector as the second derivative of "x" over t and substitute t = 3 seconds: = 6t = 18 m/s^2. Calculate the magnitude of the acceleration as | a | = = = = m/s^2. Use your calculator to get the numerical value.