A ladder, 5 meter long, standing on a horizontal floor, leans against a vertical wall. If the top to the ladder slides down wards at the rate of 10 cm/sec, then find the rate at which the angle between the floor and ladder is decreasing when lower end of ladder is 2 meters from the wall.

A ladder, 5 meter long, standing on a horizontal floor, leans against a vertical wall. If the top to the ladder slides down wards at the rate of 10 cm/sec, then find the rate at which the angle between the floor and ladder is decreasing when lower end of ladder is 2 meters from the wall.

Given that . We have to find when h=2m

Also – (1)

At b=2m,

Differentiating (1) with respect to t, we get

Substituting values, we get

⇒

1