**Unformatted text preview: **. . . . . . . . . Figure 6.15 Car and airplane. 23. Referring again to example 6.18 , suppose that instead of car B an airplane is ﬂying at speed 200 km/hr to the east of P at an altitude of 2 km, and that it is gaining altitude at 10 km/hr. How fast is the distance between car and airplane changing? ⇒ 24. A light shines from the top of a pole 20 m high. An object is dropped from the same height from a point 10 m away, so that its height at time t seconds is h ( t ) = 20-9 . 8 t 2 / 2. How fast is the object’s shadow moving on the ground one second later? ⇒ 25. The two blades of a pair of scissors are fastened at the point A . Let a denote the distance from A to the tip of the blade (the point B ). Let β denote the angle at the tip of the blade that is formed by the line AB and the bottom edge of the blade, line BC , and let θ denote the angle between AB and the horizontal. Suppose that a piece of paper is cut in such a...

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- Fall '07
- JonathanRogawski
- Math, Calculus, Derivative, Miles per hour, β, 6 seconds, 8 seconds