M E N U
DIRECTIONS
1. USEFUL FORMULAS
2. THE CIRCLE (3 VARIATIONS)
3. THE SPHERE (2 VARIATIONS)
4. THE SQUARE (2 VARIATIONS)
5. THE CUBE (2 VARIATIONS)
6. THE RECTANGLE
7. THE AIRPLANE
• 8. THE SLIDING LADDER
9. MAKING SHADOWS
10. THE CONICAL TANK
11. THE CONICAL PILE
12. FLYING A KITE
13. REVOLVING SEARCHLIGHT
14. TRAVELING CARS (2 VARIATIONS)
15. MORE SHADOWS
16. THE BASEBALL FIELD
17. THE CYLINDRICAL TANK
18. EQUATION ONE (2 VARIATIONS)
19. EQUATION TWO (2 VARIATIONS)
20. EQUATION THREE (2 VARIATIONS)
21. EQUATION FOUR (2 VARIATIONS)
22. EQUATION FIVE (2 VARIATIONS)
23. EQUATION SIX (2 VARIATIONS)
24. EQUATION SEVEN
25. THE REVOLVING BEACON
26. THE ISOSCELES TROUGH
27. THE SPACE SHUTTLE
28. GONE FISHING
29. THE CLOCK
30. THE TRIANGLE #1
31. THE TRIANGLE #2
32. THE SNOWBALL
33. THE OTHER AIRPLANE
34. YET ANOTHER SHADOW
35. THE BASKETBALL SHADOW
36. MAKING COFFEE

THE MOVING LADDER PROBLEM

A 65 foot ladder is leaning against the wall of a very tall building. The base of the ladder is pushed toward the wall at a rate of 4.5 feet/second. At the instant that the base of the ladder is 63 feet from the base of the wall, find the following:

(A) At what rate is the distance between the top of the ladder and the ground changing?


(B) At what rate is the area of the triangle between the ladder, wall, and ground changing?


(C) At what rate is the angle formed by the ladder and the wall changing?