PLEASE SHOW WORK A 25 meter ladder leans against a wall. It starts sliding from 15 meters above the ground. The foot of the ladder is pulled away from the wall at the rate 6 m/sec. What is the rate (in m/sec) at which top of the ladder is sliding down?

A. -3
B. -5
C. -8
D. -11
E. -7

Suppose, initially the ladder is so close that height of the ladder, which is 10 m to the point at which its upper end has reached.

When we pull the bottom of the ladder to such a place that it has come down by 7 m and its upper end is now 3 m from the ground. If we take the base y m, then

Using Pythagorus theorem,

y2 = 10^2 - 3^2 = 100 - 9 = 91

y = 9.54 m

The speed by which ladder was pulled was 2 m/min

So time taken to cover 9.54 m woulds be 4.77 min

As the ladder has come down by 7 m in 4.77 min, its speed for coming down was 7/4.77 = 1.47 m/min