Drops of rain fall perpendicular to the roof of a parked car during a rainstorm. The drops strike the roof with a speed of 12m/s, and the mass of rain per second striking the roof is 0.035 kg/sec. (a) Assuming the drops come to rest after striking the roof, find the average force exerted by the rain on the roof. (b) If the hailstones having the same mass as the raindrops fall on the roof at the same rate and with the same speed, how would the average force on the roof compare to that found in part (a)?