Answer: 6.86 ft per second
Explanation:
Both the top and the bottom of the ladder will be moving at the same time.
Given that the base of the ladder is pulled away from the wall at a rate of 2 feet per second when its base is 7 feet from the wall. Then the time will be
Speed = distance/time
2 = 7/t
t = 7/2 = 3.5 seconds
Using pythagorean theorem to get the length L of the wall
L^2 = 25^2 - 7^2
L = 24
The ladder will move down the length at the same time.
Rate = 24/3.5
Rate = 6.86 ft/s