Answer:
168 m
Step-by-step explanation:
First of all we need to rememeber the formula to calculate the distance with the acceleration:

Now as we do not have time, we have to use first the formula for acceleration but cleared for time:

We clear time and are left with:

Now we insert the values we know:




Now that we have time we just have to insert the values into the first formula:





And the distance that he traveled while accelerating is 168m.