不明白继续追问
望采纳
T = 27 ℃ = 300 K
P0 = 1.00 * 10^5 Pa
P1 = 1.40 * 10^5 Pa
△P = 0.40 * 10^5 Pa
P2 = P0 - △P = 0.60 * 10^5 Pa
L1 = 0.3 cm
P1L1 = P2L2
L2 = P1L1/P2
= 1.40 * 10^5 * 0.3 / 0.60 * 10^5
= 0.7 cm
= 0.007 m = 7*10^-3
答:空气柱的长度L2是0.007米