Title: Related Rates PostVideo Questions
Course: Calculus Videos Project Modules

Q: A circle's radius, [Image: equation], is increasing at a rate of 3 inches per second, as shown below. How quickly is its area increasing? (The formula for the area of a circle is [Image: equation].)
[Image: image]
- [Image: equation] square inches per second (Incorrect)
- [Image: equation] square inches per second (Incorrect)
- [Image: equation] square inches per second (Correct)
- [Image: equation] square inches per second (Incorrect)
- There is not enough information to answer this question (Incorrect)
A: [Image: equation] square inches per second

Q: A submarine is diving at a rate of 50 feet per minute. As the sub descends, the water temperature outside is falling at a rate of 0.5 degrees per foot. let [Image: equation] be the depth of the submarine. Let [Image: equation] be the temperature outside the submarine. How quickly is the temperature falling?
- 25 degrees oer minute (Incorrect)
- -25 degrees per minute (Correct)
- 0.5 degrees per foot (Incorrect)
- 100 degrees per minute (Incorrect)
- There is not enough information to answer this question (Incorrect)
A: -25 degrees per minute

Q: A rectangle has a constant height of 6 cm, as shown below. The area of the rectangle is given by the formula [Image: equation], where [Image: equation] is the length of the base of the rectangle and [Image: equation] is the height of the rectangle. In order to determine how fast its area is changing at the instant that the base has length 8 cm, which of the following formulas would you use?
[Image: image]
- [Image: equation] (Correct)
- [Image: equation] (Incorrect)
- [Image: equation] (Incorrect)
- [Image: equation] (Incorrect)
A: [Image: equation]