In Rt△ABC,

∵AC=2.5, BC=0.7, which is obtained by Pythagorean theorem.

∴AB=2.4，

AE = 0.4，

∴BE=AB-AE=2，

EF = 2.5，

∴ BF= 1.5 by Pythagorean theorem,

BC = 0.7，

∴CF=0.8.

That is, the bottom of the ladder will slide 0.8 meters.

The answer to the second question is 5.