PLEASE HELP!!!!
A race car driving under the caution flag at 120 feet per second begins to accelerate at a constant rate after the warning flag. The distance traveled since the warning flag in feet is characterized by 30t2 + 120t, where t is the time in seconds after the car starts accelerating again. How long will the car take to travel 150 feet?

It takes the car _____ second(s) to travel 150 feet.