[填空题]
Estimate the time between each photoflash ofg 8+4+ mdtbkv3bv/dvf the apple in Fig. 2–18 (or nu1:)bt;n v2f hl uye6ypmber of photoflashes per second). Assume the apple is about 10 cm in diame;2 n 6y u:eh1bfvy)tplter. [Hint: Use two apple positions, but not the unclear ones at the top.]
T = s
flashes per second