Acar moves at a velocity of 8.5 meters per second. it then accelerates at a constant rate of 2.5 m/s^2 for a total time of 5 seconds. how fast is the car moving at the end of the 5 seconds?

i got 21 is this right?

Students in an introductory physics lab are performing an experiment with a parallel-plate capacitor made of two circular aluminum plates, each 11 cm in diameter, separated by 1.0 cm. how much charge can be added to each of the plates before a spark jumps between the two plates? for such flat electrodes, assume that value of 3×106n/c of the field causes a spark.