With derivatives or by integrating the velocity function over the given interval. Because vf vi at you know that. Now put the values in the formula.
The velocity formula is normally presented as a quadratic equation.
Enter 50 in the time box and choose seconds from its menu. You still need the distance and you can get it this way. T s 2 60 120 s. Divide both sides by 2 s and reverse the equation to get.