[填空题]
A softball having a mass of 0.25 kg ispl6dmwke 7; )1g +flhy pitched at By the time it reaches+ /uqu6ykgm3 n6o4 xp9ov (6vivgtlo; the plate, it vu9m4;gn i( kx+/v6plyquto66g3o ov may have slowed by 10%. Neglecting gravity, estimate the average force of air resistance during a pitch, if the distance between the plate and the pitcher is about 15 m. N
