A 2.3 kg ball strikes a wall with a velocity of 6.3 m/s to the left. The ball bounces off with a velocity of 4.3 m/s to the right. If the ball is in contact with the wall for 0.38 s, what is the constant force exerted on the ball by the wall? Answer in units of N.

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.