A motorist travelling along a straight portion of highway is decreasing the speed of his automobile at a constant rate before exiting from the highway onto a circular exit ramp with a radius of 170m. he continues to decelerate at the constant rate so that 10 sec after entering the ramp his speed has decreased to 32kmph a speed which he then maintains knowing that at this constant speed the total acceleration of the automobile is equal to one quarter of its value prior to entering the ramp determine the maximum value of the total acceleration of the automobile.