A -ft ladder leans against a vertical wall

MATHEMATICS · Single correct · CBSE · Mathematics · Applications of Derivatives · Applications of Derivatives

Problem

25

-ft ladder leans against a vertical wall, forming an angle

\theta

(in radians) with the ground. The foot of the ladder is sliding away from the wall at a rate of

2\,\text{ft/s}

. What is

\dfrac{d\theta}{dt}

when the foot of the ladder is

7\,

ft from the wall? (a)

\dfrac{1}{12}\,\text{rad/s}

(b)

-\dfrac{1}{12}\,\text{rad/s}

(c)

-\dfrac{1}{6}\,\text{rad/s}

(d)

-\dfrac{7}{24}\,\text{rad/s}