(Solved): A motorist starts from rest at point \( A \) on a circular entrance ramp when \( t=0 \) s, increas ...

A motorist starts from rest at point \( A \) on a circular entrance ramp when \( t=0 \) s, increases the speed of her automobile at a constant rate and enters the highway at point B. Knowing that her speed continues to increase at the same rate until it reaches \( 100 \mathrm{~km} / \mathrm{h} \) at point \( \mathrm{C} \), determine (a) the speed at point \( \mathrm{B} \), (b) the magnitude of the total acceleration instantaneously right before it reached B. Hint: arclength \( = \) theta * radius.