A 25-foot ladder is leaning against a vertical wall (see figure) when Jack begins pulling the foot of the ladder away from the wall at a rate of 0.5 ft/s. How fast is the top of the ladder sliding down the wall when the foot of the ladder is 7 ft from the wall? 25 ft Let x be the distance from the foot of the ladder to the wall and let y be the distance from the top of the ladder to the ground. Write an equation relating x and y. Differentiate both sides of the equation with respect to t. dt When the foot of the ladder is 7 ft from the wall, the top of the ladder is sliding down the wall at a rate of