A Question $14(1$ point$)$ Retake question

On a hot summer day, the police have set up speeding checkpoints along a busy

highway. Just as Phillipe drives past the first checkpoint, he begins to accelerate at a

constant rate. $8\mathrm{.}35s$ later, Phillipe is $249m$ from the checkpoint and his speed is

then $39\mathrm{.}4\frac{m}{s}.$ What is Phillipe's acceleration