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 CYLINDRICAL RESERVOIR PROBLEM

A reservoir in the shape of a right cylinder has a height of 70 feet and a radius of 13.5 feet and water is leaking from the bottom the reservoir at a rate of 4 ft3/min. At the instant that the depth of the water is 20 feet, determine the following:

(A) The rate at which the radius of the surface of the water is changing.


(B) The rate at which the depth of the water is changing.