Question

The top of a ladder 6 metre long is resting against a vertical wall on a level pavement, when the ladder begins to slide outwards. At the moment when the foot of the ladder is 4 metres from the wall, it is sliding away from the wall at the rate of 0.5 m/sec. How fast is the top - sliding downwards at this instance?

Answer 1

Given: the top of a ladder 6 metre long is resting against a vertical wall on a level pavement, when the ladder begins to slide outwards, at the moment when the foot of the ladder is 4 metres from the wall, it is sliding away from the wall at the rate of 0.5 m/sec

Hence the angle θ between the ladder and the ground is changing at the rate of - 0.11 rad/sec when the foot of the ladder is 4 m away from the wall.