Title: Related Rates Post-Video Questions
Course: Calculus Videos Project > Section: Related Rates

Q: A rectangle has a constant height of 6 cm, while the base is growing at a constant rate of 3 cm/sec, as shown below. The area of the rectangle is given by the formula , where is the length of the base of the rectangle and 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?
A: (a choice with no text)

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 be the depth of the submarine. Let be the temperature outside the submarine. How quickly is the temperature decreasing?
- 25 degrees per minute
- 50 degrees per minute
- 0.5 degrees per foot
- 100 degrees per minute
- There is not enough information to answer this question
A: 25 degrees per minute

Q: A circle's radius, , 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 .)
- square inches per second
- square inches per second
- square inches per second
- square inches per second
- \(6\pi r\) square inches per second
- There is not enough information to answer this question.
A: \(6\pi r\) square inches per second