A 12 foot ladder is leaning against a wall. If the top slips down the wall at a rate of 4 ft/s, how fast will the foot be moving away from the wall when the top is 7 feet above the ground?

Answer 1

w^2 + g^2 = 12^2
... 7^2 + g^2 = 12^2
... g = √95

2 w dw/dt + 2 g dg/dt = 0

(2 * 7 * -4) + (2 * √95 * dg/dt) = 0

solve for dg/dt