A ladder 15 meters long leans against a vertical wall. If the foot of the ladder is being pulled away from the wall at the rate of 2 meters per minute. How fast is the top of the ladder sliding down the wall at the instant when the foot of the ladder is 12 meters from the wall.

1 answer

x^2+y^2 = 225
x dx/dt + y dy/dt = 0

now just plug in your numbers and solve for dy/dt