Section 3.9 Related Rates 1. (6 pts) A plane flies horizontally at an altitude of 7 km and passes directly over a tracking telescope on the ground. When the angle of elevation is x/3, this angle is decreasing at a rate of x/3 rad/min. How fast is the plane traveling at that time? 2. (6 pts) Boyle's Law states that when a sample of gas is compressed at a constant temperature, the pressure P and volume I' satisfy the equation PV = C, where C is a constant. Suppose that at a certain instant the volume is 300 cm , the pressure is 200 kPa, and the pressure is increasing at a rate of 15 kPa/min. At what rate is the volume decreasing at this instant