12 ft A B --

4. A 15-foot long ladder rests along a vertical wall. Its top slides down the wall while its bottom moves away from the wall along the level ground at a speed of 2 feet per second. How fast is the angle between the top of the ladder and the wall changing when the angle is π/3 radians?

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At noon, ship A is 10 nautical miles due west of ship B. Ship A is sailing west at 19 knots and ship B is sailing north at 20 knots. How fast (in knots) is the distance between the ships changing at 3 PM? (Note: 1 knot is a speed of 1 nautical mile per hour.)   A street light is at the top of a 19 ft tall pole. A woman 6 ft tall walks away from the pole with a speed of 8 ft/sec along a straight path. How fast is the tip of her shadow moving when she is 50 ft from the base of the pole? A circle is inside a square.The radius of the circle is increasing at a rate of 5 meters per minute and the sides of the square are decreasing at a rate of 1 meter per minute.When the radius is 5 meters, and the sides are 16 meters, then how fast is the AREA outside the circle but inside the square changing?