CALCULUS

WORKSHEET 2 ON RELATED RATES

Work these on notebook paper.

1. The top of a 25-foot ladder is sliding down a vertical wall at a constant rate of 3 feet per

minute. When the top of the ladder is 7 feet from the ground, what is the rate of change of the

distance between the bottom of the ladder and the wall?

(A) 7

8 feet per minute (B)

7

24 feet per minute (C)

7

24 feet per minute

(D) 7

8 feet per minute (E)

21

25 feet per minute

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2. (2003) The radius of a circle is increasing at a constant rate of 0.2 meters per second. What is the

rate of increase in the area of the circle at the instant when the circumference of the circle

is 20 meters?

(A) 20.04 m / sec (B) 20.4 m / sec (C) 24 m / sec

(D) 220 m / sec (E) 2100 m / sec

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3. A man 6 ft tall walks at the rate of 4 ft/sec toward a streetlight that is 16 ft above the

ground. At what rate is the length of his shadow changing when he is 7 ft from the base

of the light?

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4. (2002 Form B – AB5)

5. (2002 – AB5)

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6. (2003 - AB5)

Answers

1. D 2. C 3. 32

ft / sec5

4.

5.

6.