Free Essay

In: Novels

Submitted By daradar14

Words 1291

Pages 6

Words 1291

Pages 6

WKST- Related Rates Date:_____________________________________

1. Find the rate of change of the distance between the origin and a moving point on the graph of [pic] if [pic]cm/sec.

[pic] [pic] [pic]

2. Find the rate of change of the distance between the origin and a moving point on the graph of [pic] if [pic]cm/sec.

[pic] [pic] [pic]

3. The radius (r) of a circle is increasing at a rate of 4 centimeters per minute. Find the rates of change of the area when. [pic] [pic]

a. r = 8 centimeters b. r = 32 centimeters

[pic] [pic]

4. The included angle of two sides of constant equal length s of an isosceles triangle is [pic]. If [pic] is increasing at a rate of ½ radian per minute, find the rates of change of the area when:

[pic] [pic] [pic]

a [pic] b. [pic] [pic] [pic]

5. The radius r of a sphere is increasing at a rate of 3 inches per minute. Find the rates of change of the volume when:

[pic] [pic]

a. r = 9 inches b. r = 36 inches

[pic] [pic]

6. A spherical balloon is inflated with gas at a rate of 800 cubic centimeters per minute. How fast is the radius of the balloon increasing at the instant the radius is:

[pic] [pic]

a. 30 cm b. 60 cm

[pic] [pic]

7. All edges of a cube are expanding at a rate of 6 centimeters per second. How fast is the volume changing when each edge is:

[pic] [pic]

a. 2 cm b. 10 cm

[pic] [pic]

8. All edges of a cube are expanding at a rate of 6 centimeters per second. Determine how fast the surface area is changing when each edge is:

[pic] [pic]

a. 2 cm b. 10 cm

[pic] [pic]

9. The formula for the volume of a cone is [pic]. Find the rates of change of the volume if dr/dt is 2 inches per minute and h = 3r when:

[pic] [pic]

a. r = 6 inches b. r = 24 inches

[pic] [pic]

10. At a sand and gravel plant, sand is falling off a conveyor and onto a conical pile at a rate of 10 cubic feet per minute. The diameter of the base of the cone is approximately three times the altitude. At what rate is the height of the pile changing when the pile is 15 feet high.

[pic] [pic] [pic] [pic]

[pic]

11. A conical tank (with vertex down) is 10 feet across the top and 12 feet deep. If water is flowing into the tank at a rate of 10 cubic feet per minute, find the rate of change of the depth of the water when the water is 8 feet deep.

[pic] [pic] [pic] [pic] [pic] [pic] [pic]

12. A trough is 12 feet long and 3 feet across the top. Its ends are isosceles triangles with altitudes of 3 feet.

[pic] [pic] b = h [pic] [pic]

a. If water is being pumped into the trough at a rate of 2 cubic feet per minute, how fast is the water level rising when the depth is 1 foot?

[pic] [pic]

b. If the water is rising at a rate of 3/8 inch per minute when h = 2, determine the rate at which the water is being pumped into the trough.

[pic]

13. A ladder 25 feet long is leaning against a wall of a house. The base of the ladder is pulled away from the wall at a rate of 2 feet per second. a. How fast is the top of the ladder moving down the wall when its base is 7 feet from the wall? [pic] [pic] [pic] b. Find the rate at which the area of the triangle is changing when the base of the ladder is 7 feet from the wall.

[pic] [pic]

c. Find the rate at which the angle between the ladder and the wall of the house is changing when the base of the ladder is 7 feet from the wall.

[pic] [pic] [pic]

14. A baseball diamond has the shape of a square with sides 90 feet long. A player running from second base to third base at a speed of 25 feet per second is 20 feet from third base. At what rate is the player’s distance s from home plate changing?

[pic] [pic] [pic]

*note- answer is negative because player is running to the left

15. A baseball diamond has the shape of a square with sides 90 feet long. A player running from first base to second base at a speed of 25 feet per second is 20 feet from second base. At what rate is the player’s distance s from home plate changing?

[pic] [pic] [pic]

*note- answer is negative because player is running to the left

16. A man 6 feet tall walks at a rate of 5 feet per second away from a light that is 15 feet above the ground. When he is 10 feet from the base of the light, a. how fast is the tip of his shadow moving? b. how fast is the length of his shadow changing?

**Note- easier to do (b) first

[pic]

b. a. [pic]

[pic] [pic]

17. The combined electrical resistance R of [pic] and [pic], connected in parallel, is given by:

[pic]

where R, [pic] and [pic] are measured in ohms. [pic] and [pic] are increasing at rates of 1 and 1.5 ohms per second, respectively. At what rate is R changing when [pic]= 50 ohms and [pic]= 75 ohms?

[pic] [pic]

18. An airplane flies at an altitude of 5 miles toward a point directly over an observer. The speed of the plane is 600 miles per hour. Find the rates at which the angle of elevation [pic] is changing when the angle is: [pic] [pic]

|a. [pic]=30 degrees |b. [pic]=60 degrees |c. [pic]= 75 degrees |

|[pic] |[pic] |[pic] |

19. When a certain polyatomic gas undergoes adiabatic expansion, its pressure p and volume V satisfy the equation [pic], where k is a constant. Find the relationship between the related rates [pic] & [pic].

[pic] [pic]

20. A ball is dropped from a height of 20 meters, 12 meters away from the top of a 20-meter lamppost. The ball’s shadow, caused by the light at the top of the lamppost, is moving along the level ground. How fast is the shadow moving 1 second after the ball is released?

[pic]

[pic] [pic] [pic]

[pic] [pic]

21. A point moves along the curve [pic] in such a way that the y-value is increasing at a rate of 2 units per second. At what rate is x changing for each of the following value?

[pic]

a. x = ½ b. x = 1 c. x = 4

[pic] [pic] [pic]

22. The edges of a cube are expanding at a rate of 8 cm/sec. How fast is the surface area changing when each edge is 6.5 cm?

[pic]

23. The cross section of a five-meter trough is an isosceles trapezoid with a two-meter lower base, a three- meter upper base, and an altitude of 2 meters. Water is running into the trough at a rate of 1 cubic meter per minute. How fast is the water level rising when the water is 1 meter deep? [pic] [pic] [pic]

24. A rotating beacon is located 1 km off a straight shoreline. If the beacon rotates at a rate of 3 revolutions per minute, how fast (in kph) does the beam of light appear to be moving to a viewer who is ½ km down the shoreline?

[pic]

[pic] [pic] [pic] [pic]

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