A ladder 5 meters long leans against a wall. When the person holding it lets go, the ladder starts sliding down the wall, increasing its speed as it falls. If the top of the ladder is moving at 1 meter per second when the bottom is 4 meters from the wall, how fast is the lower end moving away from the wall at that time? Draw a diagram, and explain clearly your choice of variables. Show your work, and write a concluding sentence as your final