Problema Solution
The top of a 20-foot ladder is sliding down a wall at a rate of 10 feet per second. How fast is the base of the ladder sliding away from the wall at the instant when the top of the ladder is 12 feet from the ground?
Answer provided by our tutors
let the height of ladder from ground is x
base lenght =square root(20^2-x^2)
rate of change in base with respect to t = (1/square root(20^2-x^2))*(-2x*dx/dt)
dx/dt = -10 feet per second
x = 12
rate of change in base with respect to t = 15 feet per second