Question

David is driving a steady 21.0m/s when he passes Tina, who is sitting in her car at rest. Tina begins to accelerate at a steady 2.50m/s2 at the instant when David passes.

How far does Tina drive before passing David?
What is her speed as she passes him?

Answer 1

david distance: 21*time
tina distance: 1/2 a time^2

they both go the same distance, in the same time. set them equal, solve for time. Then calculate distance.
Her final speed=a*time

Answer 2

115.2